Through analyzing a 220 kV line short-circuit fault trip, the reasons for the inconsistent action reports of the PRS-753 line protection device and the PSL-603 line protection device for the development of the fault and the scene defects that affect the protection action are found out. The optimization logic of the application of the protection device message is proposed, so that the dual protection device can accurately and completely record the fault condition and protection action when such a fault occurs in the high-voltage line, so as to make it easier for the relay protection personnel to analyze and deal with the fault defect .