Abstract: To accurately detect the distribution of wash zone in coal working surface, based on the theory of mine radio penetration method,this thesis simulated the characteristic curve of radio wave pit penetration value of coal seam wash zone, and discussed the feasibility of detecting wash zone by radio penetration method. An experiment was carried out at a coal mine in the Tieshannan Coal Mine.This study concluded that the existence of coal seam wash zone could cause abnormal regional of radio wave penetration. Compared to the received value of normal coal receiver, abnormal curve of coal seam wash zone showed a whole smaller received value, and the attenuation was larger in middle area of model, the relative attenuation was smaller on both sides of model. The pattern formation was a "bat" shape. This method of radio wave penetration could be more reliable detection for coal seam wash zone after experimental verification in underground coal mine.