The ninth mining area of 2971 west working face of Qianjiaying Mine is the first working face. The hydrogeological conditions in the ninth mining area are relatively complex. The aquifer of the No. 5 coal seam roof with medium water yield, is relatively strong in some parts. The comprehensive geophysical exploration technology combined with advanced water discharging technology and scientific water drainage system to deal with water prevention and control, which ensured the safe mining.