There were water burst and sand in Baiyinhua No. 4 Mine 3101 working face drilling, in order to find the position of working face roof water-bearing quicksand layer and drainage it before recover mining, Hebei Coal Science Research Institute conducted voice frequency electricity penetration detection to the working face, the abnormal aquifer of working face roof was explored. The result showed that No. 2 inspection spot was abnormal, locating under No. 24 ~No. 27 inspection spot, extending 100 m into the working face, the abnormal area was large, with strong amplitude.