Abstract: A method of stowing a goaf of potash salt ore comprising making wall slurry into barricades each have the same area as the sectional area of a tunnel and a thickness of 0.5 to 5 meters inside the underground tunnels in goaf of potash salt ore, with the interval between adjacent barricades being 5 to 100 meters, then stowing the interval between the barricades by using the filling slurry is described. The stowing method uses the wall slurry of high strength that is solidified with a gelling agent as the main bearing material, and uses the solidified filling slurry with a low strength as the main filling material, which has a good effect when compared with conventional filling materials. Moreover, the stowing method effectively utilizes the tail liquids, thereby reducing the addition of other additives, decreasing the cost, avoiding the discharge of liquid waste and relieving the environmental pressure.