Abstract: There are some problems in traditional voice system of coal mine working face, for example, analog voice signals are unsuited to long haul transmission and easy to be disturbed, battery power is consumed quickly, loss of transmission line leads to super low terminal voltage, too much invalid broadcast causes power waste of intrinsically safe power supply, etc. In order to solve above problems, an intelligent voice system of coal mine working face was proposed which was based on digital voice signal transmission. Hard circuit scheme of the system was introduced as well as dynamic management scheme of voice device. The system takes CAN bus as transmission carrier of digital voice. Main controller collects status data of voice device real-timely through CAN bus, and adjusts parameters of charging current and broadcasting volume of voice device according to different rules. The industrial test shows that the system can run stably for long.