Abstract In this paper, the panel smooth transition regression model (PSTR) is used to investigate the impact of foreign direct investment (FDI) and outward foreign direct investment (OFDI) on the quality of export products under the nonlinear framework. The research finds that: 1)The nonlinear model is more suitable for the study of the relationship between FDI, OFDI and export product quality than the linear model. 2)FDI and OFDI have a highly stable and significant improvement effect on the quality of export products, and the promotion effect of OFDI is greater than that of FDI. 3)The impact of RMB real exchange rate on the quality of export products tends to be short-term and has a significant nonlinear positive impact. In addition, the impact of GDP in export destination countries tend to be long-term, and that of foreign direct investment is somewhere in between. Therefore, studies have shown that the government should continue to adhere to both the “bringing in” and “going global” strategies. Specifically methods such as tax incentives and simplification of approval procedures should be taken to expand the scales of “bringing in” and “going global” so as to jointly promote the quality upgrade of China’s export products.