In response to a series of former US President Trump sanctions on China’s entity companies and the influence of Covid-2019 , by categorizing it to target typical companies and industries that exert extreme pressure on China’s high-tech companies: Huawei, ZTE, chip industry, nuclear power industry, Aerospace industry, electronic technology industry, etc. Then, from the perspective of industrial supply chain security, on the basis of questionnaire surveys, principal component analysis, nearest neighbor analysis, neural network analysis and other methods are used to study the reasons for the US entity list, and the impact of the entity list on the industries of China and the United States. The degree of supply chain influence, finally, put forward some policies and suggestions to solve this problem.

Targeting at the problems in the risk assessment and control processes of the letter of credit settlement in China’s export enterprises so far, it first adopts the quantitative method and exploratory factor analysis to extract the main factors. On the basis, the software VENSIM is used to design the dynamics causes tree and the flow chart of the letter of credit system. Next, the equation sets of DANAMO parameters are also constructed with the software. Finally, through observation of the system risk fluctuation diagram with system simulation, it gives enterprises some advice on how to identify risk points and how to prevent and control letter of credit risks in advance.