The invention relates to a system and method for testing a power quality monitoring device. The system for testing the power quality monitoring device comprises a power quality standard source, a signal collection device, a GPS time calibration device, a protocol converter, a test station and a tested device, wherein the power quality standard source is connected with the signal collection device and the tested device through the GPS time calibration device, and the test station is connected with the tested device and the signal collection device. The method for testing the power quality monitoring device comprises the steps of (1) starting the device, (2) carrying out GPS time synchronization, (3) receiving an instruction, generating a test signal, (4) enabling the tested device to receive the test signal, storing measured data in the test station, (5) enabling the test station to receive a power quality index standard value uploaded by the signal collection device, and (6) calculating indexes of the tested device through receiving of the power quality index standard value and measured values of the tested device, and generating a test result report. According to the system and method for testing the power quality monitoring device, testing of measurement accuracy of the power quality monitoring device and testing of a measuring method can be achieved, and working efficiency is greatly improved.