Abstract: To address the issues of complex working logic and the difficulty in analyzing protection operation logic during faults in pilot current differential protection for transmission lines, a simulation model of a dual-source power supply network and the pilot current differential protection system was established using Simulink. Simulation parameter settings and result analysis were conducted based on the model. The results demonstrate that the simulation model is capable of visualizing the complete process, including the phase relationship of currents on both sides of the line, the characteristics of high-frequency signals received, and the logical outputs of the receiver and protection system before and after a fault. This model holds significant value for analyzing protection issues, and verifying the rationality of protection parameter settings.