Dynamic Risk Assessment of Port Investment in Countries along the Belt and Road

China's port investments in countries along the Belt and Road are growing, while the global investment environment has deteriorated due to the Sino-US trade friction and the COVID-19 epidemic. However, the recent quantitative research on overseas port investment risk has not considered the time weight, and the related research is less. Therefore, this paper proposes a dynamic evaluation method specially for port investment risk of countries along the B&R based on entropy weight-TOPSIS and BP neural network. First, we figure out the static comprehensive risk value by entropy weight-TOPSIS method, and get the dynamic comprehensive risk value by time weighting method. Second, select three-dimensional data of 32 indicators in 18 host countries from 2010 to 2019 for empirical analysis, and obtain the risk level of each country. Lastly, compared with multiple regression, ridge regression, partial least square, we find BP neural network is the most effective means to estimate the simulation weight of evaluation indicators. The experimental result shows that, the proposed dynamic risk assessment approach for overseas port investment is able to assess risk well and can be extended to other fields.