Abstract: The extremely severe conditions of icing and strong wind pose a great threat to the safe operation of transmission tower line system. In order to monitor the safety status of transmission tower line system in real time, this paper designs a targeted safety assessment model. Firstly, the characteristic state parameters of transmission tower line system under wind and ice load are found out by using finite element model analysis; secondly, the safety evaluation model is designed based on online monitoring data. According to the data of finite element model and expert knowledge, the fuzzy membership function is constructed and the weight is determined by analytic hierarchy process（AHP）. Finally, the feasibility of the evaluation model is verified by an engineering example.