In order to solve the problem of traditional electromagnetic geophone which can only be measured in point and high engineering cost, a distributed optical fiber acoustic sensing system is proposed. Firstly, the optical structure of the system is designed, then the key module PIN photodetector is designed. Finally, the single vibration signal in the range of 50~500 Hz is tested by using 24-core armored optical cable in four groups of frequency tests. The experimental results show that the distributed optical fiber acoustic sensing system has a good detection effect on vibration signals generated by vibroseis, and can realize the precise positioning and frequency detection of vibration sources.