Abstract: This study regards the establishment of national poverty counties as a large-scale quasi-natural experiment, and by matching the economic and social development data of Yunnan Province from 2007 to 2018 with the data of poor counties, the effect of the establishment of national poverty counties on the ability of regional coordinated development and its mechanism of action are tested. The study found that the overall level of regional coordinated development capacity in Yunnan Province is low, and the spatial distribution pattern is low around the middle and high, and the establishment of state-level poverty-poor counties can continuously and effectively promote the improvement of regional coordinated development capacity, with an average effect of 13.90 percent, and with the establishment of national poverty-poor counties for longer, the improvement of regional coordinated development capacity is more obvious, and the implementation of precision poverty-relief strategy is a clear dividing point. In this paper, PSM-DID method is used to reduce endo-nature problems, change matching method and adjustment of matching variable indicators and other robust tests, the conclusion is still sound, the mechanism analysis shows that the impact of the establishment of poor counties on regional coordinated development capacity from the optimization of industrial structure, capital accumulation and fiscal revenue and expenditure dilemma improvement three paths, and mainly through infrastructure access to improve the realization.

Key words: national poverty-stricken county, regional coordinated development capacity, PSM-DID, regional development