Based on the provincial panel data from 1994 to 2016, the economic quality index of China’s provinces was calculated by constructing a highquality economic development index system, and difference in differencepropensity score matching (PSMDID) was used to test the net policy effect of western development. It can be found that on the whole western development has promoted the highquality economic development of Western China, but at the same time there are problems such as a single infrastructure construction and investment direction, and insufficient foreign investment and innovation capabilities. Therefore, the adjustment of western development should be to continue to increase financial investment, gradually adjust investment direction, eliminate backward industries, transform traditional industries, develop advantageous industries; strengthen preferential policies, improve the soft environment for business, strengthen incentive mechanism of talents and local innovation ability, increase the intensity of environmental regulation and prevent the transfer of polluting enterprises.

western development;highquality economic development;the net policy effect;difference in differencepropensity score matching