Accurate identification of fault control parameters is the basis for establishing an accurate simulation model of a grid-connected photovoltaic system.The dynamic coupling of multiple control links and the low sensitivity of some parameters lead to a low overall identification accuracy of control parameters.To address this problem，an identification method for control parameters of a grid-connected photovoltaic system based on sensitivity characteristic analysis is proposed in this paper.Firstly，a method of injecting disturbances into the measurement signals on the secondary side of the system is proposed to decouple the dynamics of multiple controllers.Secondly，a sensitivity algorithm is used to analyze the dynamic correlation between the control parameters and the system fault transient current，and the optimal observation time window is selected.Thirdly，the sensitivity differences of control parameters under different types of disturbances are used to identify the control parameters step by step，which effectively solves the problem that multiple control parameters are difficult to be identified simultaneously.Finally，a 29-node simulation test system with grid-connected photovoltaics is built on the MATLAB/Simulink platform，and the effectiveness of the proposed method is verified.