Abstract: This paper uses the multi-input and multi-output comprehensive operating efficiency index measured by the DEA-EBM model as a measure of the company’s operating performance, and divides the types of corporate environmental protection expenditures into green investment and green expenses, empirically test their differential impact on operating performance, on the basis of this, we further from multiple angles such as technological innovation, productive capital investment, financing constraints, systemically examine the specific transmission paths of environmental protection expenditures such as green investment that affect the operating performance. The results show that: green investment and operating performance present a “U-shaped” relationship that inhibits first and then promotes, and there is a negative relationship between green expenses and operating performance; technological innovation and productive capital investment play an intermediary role in the “U-shaped” relationship between green investment and operating performance, productive capital investment plays an intermediary role in the negative relationship between green expenses and operating performance, and financing constraints do not play a significant intermediary role in the relationship between green investment, green expenses and operating performance. In addition, we further analyze the heterogeneity of the non-linear impact of green investment on operating performance, and find that companies belonging to areas with low environmental supervision or high degree of marketization can have a significant non-linear impact of green investment on operating performance; companies with state-owned property rights have a greater and more significant non-linear impact on operating performance. The paper suggests that enterprises should increase green investment and technological innovation,the government should formulate differentiated and dynamically adjusted environmental supervision intensity, and accelerate the process of market-oriented reform, so as to give full play to the promoting effect of green investment on operating performance.