In the context of economic globalization and increasingly tight resource and environmental constraints, the en-vironmental effect of open economy has been highly concerned by the academic community. With the imple-mentation of the“Going Global”campaign and the“Belt and Road Initiative”, China \' s OFDI has been expand-ing. What is the impact of the rapid growth of OFDI on the home environment? How can China improve the quality and level of OFDI in order to promote domestic green development under the dual context of con-structing a new dual circulation development pattern and advocating green development? These questions de-serve further discussion. Most of the existing literature focuses on the empirical interpretation of OFDI \' s home country environmental effect by using linear models, while few involve nonlinear models. The literature on the important role of financial development in home country and the threshold effect of OFDI on home coun-try environment is even less common. In view of this, based on the mechanism of argumentation and proposi-tional inference, this paper calculated the environmental pollution index of 30 provinces in China from 2003 to 2017 by using China \' s provincial panel data of these years and selecting industrial waste water, industrial waste gas, industrial SO2 , and industrial soot emissions and industrial solid waste production amount index. Then, this paper empirically studied China\'s OFDI home environment of financial development threshold ef-fect by constructing financial development as the threshold variables panel threshold model. The results showed that:①China \' s OFDI had a significant impact on the environment of the home country, based on the level of financial development of the home country. When China \' s financial development level was lower than the first threshold value, China \' s OFDI had a significant restraining effect on environmental pollution in the home country. When China \' s financial development level crossed the first threshold value but did not ex-ceed the second threshold value, China \' s OFDI significantly enhanced its inhibiting effect on environmental pollution in its home country. When China \' s financial development level was higher than the second thresh-old value, the inhibiting effect of China \' s OFDI on environmental pollution in the home country was further enhanced. ② In the sample period, the financial development level of most provinces in China was not high. Only a few provinces with high financial development level had a strong inhibiting effect on environmental pollution in their home country, and the provinces with a high degree of coupling and coordination between OFDI and financial development tended to have a low level of environmental pollution. Accordingly, this pa-per proposes to optimize the financial service environment of OFDI, improve the green technology content of OFDI, and strengthen the original innovation and re-innovation ability of green technology.