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近年来，贸易保护主义抬头，逆全球化势头高涨，新冠疫情的冲击挥之不去， 全球经济不稳定不确定性明显增强。从国内环境看，中国正处于经济增速换挡期、 结构调整阵痛期、前期刺激政策消化期三期叠加的阶段，改革发展稳定任务艰巨。 面对当前中国经济发展的新环境和新阶段，双循环新发展格局应运而生。2020 年 5 月 14 日，中央提出“深化供给侧结构性改革，充分发挥我国超大规模市场优势 和内需潜力，构建国内国际双循环相互促进的新发展格局”。其中，双循环发展 理念应以畅通国内经济大循环为核心与重点，但在构建全国统一大市场、畅通国 内大循环的过程中却面临着中国特有的国内市场分割现象。这一现象的长期存在 不仅会阻碍商品和要素在国内自由流动，还会削弱市场机制优化资源配置的效率， 最终阻碍经济发展。大量研究已经证明，金融发展在提高经济效率方面具有重要 的作用，具体表现为促进全要素生产率的提升和产业结构的优化升级。随着数字 技术持续赋能我国金融行业，数字金融已经发展成为一种兼具“普惠性”和“高效 性”的新型金融模式。因此，深入研究数字金融对于缓解市场分割，促进经济发 展的具有重要现实意义。 本文首先在理论上阐述数字金融发展对国内市场分割的影响机制；在作用机 制方面，一是数字金融发展通过促进居民消费水平提高和消费结构升级，推动商 品要素跨地区流动，有助于弱化我国的市场分割。二是数字金融发展可以显著提 高投资的广度和深度，推动产业结构升级，促进地区间的商品要素流动，削弱国 内市场分割程度；在异质性分析方面，数字鸿沟的普遍存在对数字金融的市场分 割弱化效应产生了重要影响，具体而言，数字鸿沟较低的地区，数字金融发展缓 解市场分割的能力较强，反之较弱。其次，基于 Dagum 基尼系数分解法和核密 度估计法分析了中国数字金融发展与国内市场分割程度的相对差异和绝对差异 及其时空特征。最后，使用 29 个地区的面板数据，实证检验数字金融发展对国 内市场分割的影响。第一，通过双向固定效应 OLS 估计证明数字金融及其三个 子指标显著削弱了国内市场分割，其中数字化程度的作用效果最明显，使用深度 次之，覆盖广度最小。为排除内生性影响，进一步通过增加控制变量、使用工具 变量和双向固定效应 2SLS 估计法进行检验。第二，考虑到关键变量的衡量和样 本误差等问题，使用互联网普及率替代北京大学数字金融发展指标、使用市场化水平指数替代市场分割指数以及剔除直辖市样本三种方法进行稳健性检验，检验 结果证实了上述结论。第三，从消费和投资两方面进行作用机制分析，发现居民 消费水平、消费结构升级以及产业结构优化在数字金融削弱国内市场分割的过程 中发挥了中介效应。第四，从数字鸿沟和地理区位两方面进行异质性分析，发现 数字金融的正效应更偏向于数字鸿沟较低的省市和东部地区的省市。第五，进一 步分析发现金融监管水平与数字金融发展不匹配将会抑制我国市场分割的弱化 效应，但随着时间推移监管红利将逐步释放。

In recent years, trade protectionism has risen, the momentum of anti globalization has soared, the impact of the COVID-19 has lingered, and the instability and uncertainty of the global economy have significantly increased. In terms of the domestic environment, China is in a period of shifting economic growth, painful structural adjustment, and digestion of early stimulus policies. The task of reform, development, and stability is arduous. In the face of the new environment and new stage of China's economic development, a new pattern of double cycle development emerged as the times require. On May 14, 2020, the central government proposed to "deepen the supply side structural reform, give full play to China's super large market advantages and domestic demand potential, and build a new development pattern of domestic and international double circulation and mutual promotion". Among them, the concept of dual cycle development should focus on unblocking the domestic economic cycle, but in the process of building a unified national market and unblocking the domestic cycle, it is facing the phenomenon of China's unique domestic market segmentation. The long-term existence of this phenomenon will not only hinder the free flow of commodities and factors in China, but also weaken the efficiency of market mechanism to optimize resource allocation, and ultimately hinder economic development. A large number of studies have proved that financial development plays an important role in improving economic efficiency, mainly reflected in the improvement of total factor productivity and the optimization and upgrading of industrial structure. As digital technology continues to empower China's financial industry, digital finance, as a new financial model with both "inclusiveness" and "efficiency", is in the ascendant. Theoretically, Digital finance can mitigate the adverse impact of market segmentation on economic development. Because of this, it is self-evident that it is important to explore the impact of digital financial development on domestic market segmentation, which is also the starting point and foothold of this paper. Firstly, this paper theoretically expounds the impact mechanism of the development of digital finance on domestic market segmentation. In terms of mechanism, first, the development of digital finance will help weaken China's market segmentation by promoting the improvement of residents' consumption level and upgrading of consumption structure and promoting the cross regional flow of commodity factors. Second, the development of digital finance can significantly improve the breadth and depth of investment, promote the upgrading of industrial structure, promote the flow of commodity factors between regions, and weaken the degree of domestic market segmentation; In terms of heterogeneity analysis, the prevalence of the digital divide has had an important impact on the weakening effect of market segmentation of digital finance. Specifically,in regions with low digital divide, digital finance development has a strong ability to alleviate market segmentation, and vice versa. Secondly, based on Dagum Gini coefficient decomposition method and kernel density estimation method, this paper analyzes the relative difference and absolute difference between China's digital financial development and domestic market segmentation, as well as their space-time characteristics. Finally, we use panel data from 29 regions to empirically test the impact of digital financial development on domestic market segmentation. First, through the two-way fixed effect OLS estimation, it is proved that digital finance and its three sub indicators significantly weaken the domestic market segmentation, of which the effect of digital degree is the most obvious, followed by the depth of use and the minimum coverage. In order to exclude endogenous effects, further tests were carried out by adding control variables, using instrumental variables and 2SLS estimation of twoway fixed effects. Second, considering the measurement of key variables and sample error, we used Internet penetration rate to replace the digital financial development indicators of Peking University, marketization level index to replace the market segmentation index, and removed the samples of municipalities directly under the Central Government to conduct robustness tests, and the test results confirmed the above conclusions. Third, through the analysis of the mechanism of consumption and investment, it is found that residents' consumption level, consumption structure upgrading and industrial structure optimization play an intermediary role in the process of digital finance weakening the domestic market segmentation. Fourthly, through the analysis of the heterogeneity of digital divide and geographical location, it is found that the positive effect of digital finance is more biased towards provinces and cities with lower digital divide and eastern regions. Fifth, through further analysis, it is found that the mismatch between the level of financial supervision and the development of digital finance will inhibit the weakening effect of market segmentation in China, but the regulatory dividend will be gradually released as time goes by.