This paper, based on a case study on Linfen coal mine, Shanxi province, uses controlled source audiofrequency magnetotelluric method (CSAMT) and transient electromagnetic method (TEM) to detect the waterfilling goaf in No.2 and No.9+10 coalbeds. CSAMT is sensitive to structure and TEM is sensitive to water, both are combined in effectively detecting the waterfilling goaf and waterbearing faults. This can provide a scientific basis for the management of waterfilling goaf, and ensure the safety and efficient production of coal mines.