The paper discussed the development and application of foam washing fluid and HJ-YS series washing fluid for Yangshan mining area of Gansu. With the cases of ZK706 in 42 exploration line, and ZK3002, ZK3016, ZKN3084 and ZK0204 in 51 exploration line, the application effect of foam washing fluid to hole wall instability is firstly introduced; then the application effect of HJ-YS series washing fluid are introduced. This low solid plant gum has lubricating resistance-reducing and wall protection effects in serious broken, multi-karst cave, leakage, high water-sensitivity and difficult coring formations.