Abstract: Now there are so many electric shock accidents because of the step voltage which is due to the water immersion electricity leakage. So through the analysis of these accidents, one kind of water immersion electricity leakage alarm device is developed. Wired and wireless detection are used in this kind of alarm device. The whole device is installed on outside of Insulated shoes and work clothes through VELCRO.Using equipotential bonding, the protection effect of Insulated shoes and work clothes are not affected. The basic principle, main functions and Single-Chip Microcomputer module are analyzed in more detail.The functions are tested by practice.It's worthy to spread.