Based on the international panel data from 2004 to 2017,this paper uses SBM model with unexpected output to calculate the global Malmquist-Luenberger productivity index,measures the level of green development of 31 countries along the Belt and Road,examines the relationship between China's OFDI and the green development of these countries,and verifies whether these countries have become a“pollution haven”of China's OFDI.The results show that China's OFDI has significantly promoted the green development level of the countries along the route,and the results are still valid after processing potential endogenous problems through instrumental variables,verifying that the countries along route are not China's OFDI's“pollution haven”.According to the sub-sample estimation results,China's OFDI has a greater green total factor growth effect in Asian countries than in European countries.By introducing two variables of infrastructure level and energy utilization level,it is found that the levels of infrastructure and energy utilization in China OFDI play a significant intermediary effect in improving the green development level of the countries along the Belt and Road,which indicates that China's OFDI can improve the basic level and energy utilization level of the countries along the Belt and Road and promote the green development in these countries.