Abstract: In order to meet the demand of microseismic monitoring in oil and gas development, a new type of underground three components optical fiber microseismic monitoring system was designed based on time-division multiplexing scheme. Combined with indoor test, the background noise of the system was less than −101 dB, dynamic range more than 120 dB, interstage crosstalk less than −67 dB, which meet the needs of microseismic signal detection. The system was successfully applied to the field detection of hydraulic fracturing microseism in Xinjiang Oilfield. The monitoring results show that the system can clearly capture the P-wave and S-wave signals of microseism, better reveal the characteristic information of hydraulic fracturing microseismic signals, and establish a good foundation for the spatial location of microseismic events and the interpretation of fracture characteristic parameters.