For the electrical life test of switch protection electrical products, there is no effective monitoring method for failure. When a failure occurs, the test system lacks effective protection. An electrical life test monitoring method was proposed, and a protection device was designed. Firstly, the characteristics of test parameters were summarized and some fault models were established. And then the hardware circuit and software program were designed to make monitoring and protection device. Finally, a certain type of low-voltage AC circuit breaker was selected for electrical life test, and the simulated failures were applied to verify the effectiveness of device. The research results show that the device accurately detects the occurrence of faults and automatically takes protective measures to ensure the safety of test system. The method and device can also be applied in other tests to solve the problem of lack of monitoring and protection.