The invention discloses a system and a method for a functional test of an overload protective card. When the functional test is performed on the overload protective card, a background host sends test case information configured by a man-machine interaction module to a front-end processor. The front-end processor resolves the test case information to a control command. A main control panel configures corresponding channels in a switching value output board. A relay protection tester configures test voltage output by the switching value output board, and outputs test voltage to an adaptive device through the switching value output board. The adaptive device performs conditioning on test voltage signals, and performs conditioning on response voltage signals output by the overload protective card. The main control panel acquires the response voltage signals output by the adaptive device through a switching value input board, and uploads the response voltage signals to the background host through the front-end processor. The background host processes the response voltage signals and the test voltage signals, and outputs the signals through the man-machine interaction module. The technical scheme solves problems that wiring is complex, efficiency is low, and requirements on operating personnel is high.