The invention relates to a portable safety instrument for miners and belongs to the field of information and automation. The instrument comprises a microprocessor, a storage circuit, a data acquisition circuit, a speech coding circuit, a wireless radio frequency module, a battery, a wireless signal repeater, earphones, a wireless video transmission module, a power supply module, a warning circuit, a serial port circuit, a keyboard circuit and a display module. The portable safety instrument is a device which can be used for learning about information on surrounding environment of a miner and realizing voice and video communication with a working field. The system of the device adopts the wireless radio frequency module to realize data transmission in a repeater mode. The safety instrument provides a good solution to problems of monitoring people, early warning and rescuing in mines, tunnels and other isolated environments. The safety instrument has the characteristics of low cost, low consumption, high performance, portability and so on, and can be used as a common portable safety instrument for miners.