Abstract: With the rapid development of national economy, the popularity of power grid cable is becoming more and more high. Because of the high defect rate of cable intermediate joint, the stable operation of power system is seriously threatened. Based on the existing problems of power cable joint, this paper studied the common detection methods of cable joint, designed an explosion-proof device of cable joint based on temperature detection method,and introduced the structure and function of explosion-proof device of cable joint in detail. The explosion-proof device can provide theoretical basis for the early detection of potential cable hazards and the reduction of failure rate, and has an important guiding role.