The terminal area is complex, the aircraft accident happens frequently, and the dangerous weather in the terminal area control area has a great influence on the safe operation of the aircraft, so it is necessary to evaluate the risk of terminal area control in dangerous weather. A risk assessment model of terminal area control system under dangerous weather conditions based on risk information entropy is proposed. Firstly, the entropy flow model of the control system is established by analyzing the operation process of the control system under the dangerous weather condition. Then the risk assessment index system of the terminal area under dangerous weather is established. The calculation method of the gray relational degree attribute of the evaluation index is given. Finally, the risk assessment model of terminal area control in dangerous weather is established, and the feasibility and effectiveness of the model are verified by an example.