Foreign direct investment，as an important part of the aggregate liquidity of an economy， has a long-term contribution to the economic growth， which depends on the complementary and substitution relationship between its actual utilized projects and the domestic financial environment and terms of trade. It also has a significant spillover effect on the investment behavior of domestic market entities. Although China's financial market has made a considerable progress in recent years， there is still financial friction such as information asymmetry and limited pledgeability.At the same time,the macro-environment of financial deleveraging causes corporations to face increased financial constraints and financing costs. At the same time，global trade protectionism is on the rise. The United States has even announced in March 2018 that it would impose large-scale tariffs on imports of goods worth 60 billion U.S. dollars from China and restrict Chinese enterprises’ investment in U.S. In this international context， this paper attempts to incorporate industry trade conditions into the unified research framework of financial constraints and foreign direct investment flows through the panel threshold model， so as to explore the potential endogenous relationships of trade conditions， financial development， and foreign direct investment.