The invention provides a live operation tool test system and method. The system comprises a test transformer, a test product carrying device, a test result output device and an automatic voltage regulating device. The automatic voltage regulating device comprises an embedded processor, a voltage regulation controller and a voltage regulator. The input end of the voltage regulator is connected with an AC power supply. The output end of the voltage regulator is connected with the test transformer. The output end of the embedded processor is connected with the voltage regulation controller. The output end of the voltage regulation controller is connected with the voltage regulator. The voltage regulator is connected with the input end of the test transformer through different output voltage taps. The test transformer amplifies voltage outputted by the voltage regulator and then loads voltage to the test product carrying device. A voltage regulation control signal is outputted to control the voltage regulation controller through the embedded processor. The voltage regulation controller controls the voltage regulator to regulate a voltage output value. No manual control is required in the whole voltage regulation process, the requirement for the operating level and operating experience of test personnel is low, degree of automation is relatively high and test efficiency is enhanced.