Abstract:     Given the continuous spread of the impact of the new crown epidemic and the tightening of foreign restrictions on China's food imports, can rural financial exclusion and agricultural technological progress become important variables to alleviate China′s food supply dilemma? In this paper, the panel data of 30 provincial-level regions in China from 2000 to 2018 are used, and we use the entropy method to measure the rural financial exclusion index, and use the DEA-Malmquist method to measure the agricultural technology progress index, and the two-way fixed effect model, the mediating effect model and the threshold regression model are used to answer the above questions. The paper draws two main conclusions through theoretical analysis and empirical analysis. First, the excessive level of rural financial exclusion will not only directly inhibit China′s food supply security, but also indirectly affect food supply security by affecting agricultural technological progress. Agricultural technological progress has an intermediary effect between rural financial exclusion and food supply security, and this intermediary effect accounts for about 26.6% of the total effect of rural financial exclusion on food supply security. On the one hand, the central bank should encourage rural financial institutions to provide more financial services to food producers through these institutional innovations, such as interest reduction or exemption, issuing more favorable loans, and providing guarantees for the risks necessary for food production. In addition, the central bank must set limits on financial institutions that provide financial services to farmers to regulate the minimum support limits for financial institutions. The second conclusion drawn by the thesis through the above analysis is that the impact of agricultural technological progress on food supply security has a non-linear threshold characteristic. When the rural financial exclusion index is greater than or equal to the threshold value of 0.679, the role of agricultural technological progress in promoting the security of food production and supply will be reduced. Therefore, we should adopt various policies and measures to reduce the level of rural financial exclusion. We should also use various means to improve the efficiency of agricultural technological progress. Through the above measures, we should ensure the overall food supply security of our country. Firstly, relevant government departments should reduce the restriction of "infiltration of industrial and commercial capital into rural areas" through institutional innovations, encourage and guide private capital to invest in grain production and business activities, and especially encourage them to invest in the development of high-quality grain seeds. And the transformation of agricultural machinery and tools. Secondly, we must give full play to the R&D advantages of universities and agricultural research institutes, and actively promote industry-university-research cooperation on food supply security in accordance with the requirements of the upper limit of the rural financial exclusion threshold verified in this paper to alleviate the negative impact of rural financial exclusion on agricultural technology advancement. In addition, it is necessary to introduce market mechanisms into food supply, build a mechanism that includes benefit sharing and risk sharing, to encourage food suppliers to engage in technological innovation, and to enhance the applicability and practicability of food production technology. 

Key words: rural financial exclusion, agricultural technology progress, food supply security, transmission mechanism, threshold regression model