Abstract: In order to satisfy the demands of fracturing wide, short and high conductivity fracture in Tuha Oilfield at medium-high water-cut stage,developed secondary sanding hydraulic research,analyzed secondary sandfrac mechanism and implementation parameters optimum.The experiment in situ obtains notable effect.This technique solved hydrofrac of close flood frontier formation,and solved the low success ratio in low sanding concentration of routine thickness fracture,and solves fissure highness when interlayer condition is poor in loosen sandstone formation and production layer is close to up-down water layer.The technique offers scientific direction and precious experience for similar layer hydrafrac.