Abstract: In response to the problems of time-consuming and labor-intensive testing of various protection trip outlet circuits and long power outage time in the acceptance of microcomputer protection renovation for 220 kV and above, a PLC programmable outlet pressure plate circuit tester is proposed. Combined with the microcomputer protection tester, the PLC internal program can simultaneously collect the potential change time limits of up to 4 trip outlet pressure plates, and display and record them separately through the human-machine interface, making the trip time limits of each circuit of the protection outlet pressure plate clear at a glance, greatly improving the debugging efficiency of complex microcomputer protection for 220 kV and above.