Abstract: In order to obtain the hydraulic fracturing influence scope of coalbed methane in underground well, according to the physical property variation features of seam and surrounding rock during the fracturing period, in combination with the exploration principle and application scope of the microseismic technology and the transient electromagnetic method, the microseismic technology and the transient electromagnetic method was combined and applied to detect the hydraulic fracturing effect of the coalbed methane in the underground well. The methane was applied to detect the fracturing influence scope of two boreholes in Xinglongzhuang Mine. The conventional borehole drilling method was applied to verify the detect results. The study showed that due to the soft seam, high attenuation of the seismic waves and the serious broken surrounding rock and seam in the fracturing area would not be favorable to have new broken block in the surrounding rock and seam in the fracturing area. A less microseismic accident was received and the fracturing influence scope set by the detection of microseismic. The surrounding rock or the seam in the fracturing area was seriously broken. The fracturing fluid was diffused along the previous fractures and the fracturing influence scope of the transient electromagnetic method was high. A comprehensive explanation was conducted on the microseismic monitoring technology and the transient electromagnetic method. The reliability and accuracy of the explained achievements was improved and the reliability and accuracy of the method also verified by the water pressure in the inspection boreholes.