近年来，受到经济周期下行以及新冠疫情等重大突发公共卫生事件的叠加影响，我国资本市场上债务违约事件越发严重。自2014年国内信用债首次发生实质性违约以来，我国债券市场“刚性兑付”的预期不断被打破，频繁且金额庞大的债务违约事件的爆发标志着债务违约已逐渐步入常态化。中小企业作为我国经济运行和发展的中坚力量，由于其自身资金规模小，抗风险能力弱等禀赋限制，以及我国传统金融体系存在着金融发展失衡、信贷结构性矛盾突出等问题，通常面临着更高的债务违约风险。因而探索中小企业债务违约风险的影响因素以及降低中小企业债务违约的可能性成为我国亟需解决的关键问题。在数字经济时代下，数字普惠金融作为一种新兴金融服务模式，通过大数据等先进的数字技术，推动了金融服务创新，优化了中小企业的融资环境，提升了金融市场的效率以及中小企业的全要素生产率，为中小企业有效防范化解债务违约风险提供了新途径。因此，深入探究数字普惠金融对中小企业债务违约风险的影响具有重要的理论与现实意义。

本文在梳理与总结国内外现有研究的基础上，选取中国创业板和中小板上市企业作为研究样本，实证检验了数字普惠金融对中小企业债务违约风险的影响，同时探讨了融资约束和全要素生产率在两者之间的中介传导机制，考察了经济政策不确定性和公司治理水平对两者关系的调节效应，并进一步探索了行业性质和产权性质对两者关系的异质性影响。研究结果表明：第一，数字普惠金融显著降低了中小企业债务违约风险，其使用深度和覆盖广度均对中小企业债务违约风险具有显著的抑制效应。第二，融资约束和全要素生产率在数字普惠金融影响中小企业债务违约风险的过程中均发挥了部分中介效应，即数字普惠金融可以通过缓解融资约束和提升全要素生产率来降低中小企业的债务违约风险。第三，经济政策不确定性在数字普惠金融与中小企业债务违约风险之间具有负向调节效应，而公司治理水平在数字普惠金融与中小企业债务违约风险之间具有正向调节效应。第四，在非国有中小企业和高新技术中小企业中，数字普惠金融对中小企业债务违约风险的抑制效应表现得更为显著。

最后根据实证结论，提出加强数字化建设，积极推动数字普惠金融发展；强化数字普惠金融风险管控，完善监管体系；疏通数字普惠金融影响债务违约风险的路径，提升抑制效应；优化外部环境，保障数字普惠金融抑制效应的发挥；把握数字普惠金融发展机遇，助力中小企业稳健发展以及注重中小企业异质性，因企施策等对策建议。

In recent years, due to the superimposed impact of the economic cycle downturn and major public health emergencies such as COVID-19, debt defaults in China's capital market have become increasingly serious. Since the first substantial default of domestic credit debt in 2014, the expectation of "rigid payment" in China's bond market has been broken, and the frequent and large amount of debt defaults has marked the gradual normalization of debt defaults. As the backbone of China's economic operation and development, small and medium-sized enterprises(SMEs) are usually faced with higher debt default risk due to their small capital scale, weak ability to resist risks and other limitations, as well as the unbalanced financial development and prominent credit structural contradictions in China's traditional financial system. Therefore, to explore the factors affecting the risk of debt default of SMEs and to reduce the possibility of debt default of SMEs has become a key issue urgently to be solved. In the era of digital economy, digital inclusion finance, as an emerging financial service mode, promotes financial service innovation, optimizes the financing environment of SMEs, improves the efficiency of the financial market and the total factor productivity of SMEs through advanced digital technologies such as big data, and provides a new way for SMEs to effectively prevent and defuse debt default risks. Therefore, it is of great theoretical and practical significance to explore in depth the impact of digital inclusive finance on the debt default risk of SMEs.

Based on the review and summary of existing studies at home and abroad, this paper selects Chinese GEM and SME listed enterprises as research samples, empirically examines the impact of digital inclusive finance on the debt default risk of SMEs, explores the mediating transmission mechanism financing constraints and total factor productivity, examines the moderating effects of economic policy uncertainty and corporate governance level on the relationship, and further exploring the heterogeneous effects of industry nature and property rights on the relationship. The research results show that: firstly, digital inclusion financial significantly reduces the debt default risk of SMEs, and its use depth and coverage breadth have significant inhibitory effects on the debt default risk of SMEs. Secondly, financing constraints and total factor productivity both play a partial intermediary effect in the process of digital inclusion financial affecting the debt default risk of SMEs, that is, digital inclusion financial can reduce the debt default risk of SMEs by alleviating financing constraints and improving total factor productivity. Thirdly, economic policy uncertainty has a negative moderating effect between digital inclusive finance and the debt default risk of SMEs, The level of corporate governance has a positive moderating effect between digital inclusion financial and the debt default risk of SMEs. Fourthly, among non-state-owned SMEs and high-tech SMEs, digital inclusive finance has a more significant inhibitory effect on the debt default risk of SMEs.

Finally, based on the empirical findings, we propose to strengthen digital construction and actively promote the development of digital inclusive finance; Strengthen the risk management of digital financial inclusion and improve the regulatory system; Unblock the path through which digital inclusive finance affects the risk of debt default and enhance the inhibiting effect; Optimize the external environment to guarantee the inhibiting effect of digital inclusive finance; Grasp the development opportunities of digital inclusive finance, help the steady development of SMEs, pay attention to the heterogeneity of SMEs, and implement targeted policies and suggestions.