The invention discloses a system and method for testing the sensitive elements of an over-current protection and voltage monitoring device. The system comprises a testing signal source, an equipment cabinet, a front-end processor, an acquisition control device, an adapting device, and a switching power supply. The front-end processor is used for receiving a testing case and analyzing the testing case as a control instruction. The testing signal source is used for receiving a control instruction. The acquisition control device is used for receiving a control instruction. The over-current protection and voltage monitoring device comprises a relay board, a main board, and a display screen. A plurality of sensitive elements on the relay board are subjected to function testing according to a testing signal. The display screen sets a setting threshold value and displays the testing signal. The main board controls the relay board to be in a normal operating state according to the setting threshold value and the testing signal. The system and method for testing the sensitive elements of the over-current protection and voltage monitoring device use an automated, intellectualized, and integrated online monitoring means and may accurately and high-efficiently test the functions of the sensitive elements in the over-current protection and voltage monitoring device.