This paper takes listed agricultural companies from 2013 to 2022 as the research object, and uses fixed effect model and threshold model to test the impact of government subsidies on agricultural enterprises' R&D input. The results show that: Government subsidies can significantly increase the R&D input of agricultural enterprises, and financing constraints have a single threshold effect in the process of the impact of government subsidies on agricultural enterprises. Government subsidies for sample agricultural enterprises on both sides of the threshold have a positive promoting effect on R&D input, and when the financing constraints are higher than the threshold threshold (FC > 0.1812), Government subsidies play a more positive role in promoting agricultural enterprises' R&D investment. The research results confirm that the relationship between government subsidies and agricultural enterprises R&D investment is not linear, and the corresponding policy recommendations are put forward according to the empirical research results.