In view of problems of high cost and low universality existed in current acquisition systems of mine microseismic signal, an acquisition system of multi-channel microseismic signal was designed. The system adopts seismometer to collect microseismic signals, uses acquisition circuit to implement amplification for microseismic signals, analog-to-digital conversion and digital filter, and uses STM32 to real-timely send filtered signals to PC for analysis by USART. The test results show that the system can accurately collect and record 3-channel microseismic signals collected by seismometer with good stability, high reliability and low cost.