Physical and mechanical properties and permeability coefficient of the tailing dam were found out by geo-technical engineering investigation and analysis calculation on dam stability was carried out. High would cause instability. Concrete without sand was taken as the caisson wall and the proper construction method was adopted to reach the designing depth. Pumping test and dewatering discharging operation proved that taking concrete without sand as caisson wall could have good permeability and filtration function, effectively lower the saturation line and increase stability of the dam.