Abstract: Songliao Basin is rich in shale oil reserves, and serves as a significant oil-gas resources replacing field. Shale oil is an important unconventional oil-gas type. Due to complex geological conditions of formation and burial, and poor reservoir physical property, its exploration and development requires hydraulic fracturing, and microseismic monitoring is an essential technology to evaluate fracturing effect. According to the surface and underground seismic geological conditions and distribution characteristics of horizontal stages in SYY-1HF well, a regular rectangular observation system is designed for ground microseismic monitoring to ensure uniform coverage of the target area in all directions. For shale oil buried below 2000 m, the fracturing microseismic signals visible to naked eyes are collected through good coupling of geophone and ground, and tomography technique is used for calculation of fracture range and inversion positioning of microseismic events. The imaging results show that the fracture formation effect is obvious after fracturing in each stage, which effectively links the fluid channel between reservoir and wellbore. The practice of microseismic monitoring has initially proved that reasonable fracturing parameter design and engineering construction can achieve good fracturing effect of shale oil; the microseismic monitoring technology is a significant and effective means to evaluate fracturing effect and provide technical support for exploration and development of shale oil.