Abstract: In view of the problem of serious security risk because a lot of important coal mine equipments were operated by non-professionals, the paper designed an underground IC card identifying on-off device, and introduced hardware constitution and software design of the device. The device adopts non-contact IC card to achieve authentication, uses non-contact IC card reader to judge whether operators are professional, and sends different commands to control explosion-proof switch to perform appropriate action according to different permissions of the different IC card. Taking the application of coal mine into account, explosion-proof enclosure and intrinsical safety power supply circuit were designed in order to ensure safe operation of the device.