The invention discloses a washing device for a dangerous material container. The washing device comprises an inner wall washing assembly, an outer wall washing assembly and a conveyor belt. The inner wall washing assembly comprises a container fixing device and a rotary spray head used for washing the inner wall of the container. The outer wall washing assembly comprises a conveying connection trigger, a rack which is provided with a cavity with an inlet and an outlet, a first abrasive blasting mechanism, a second abrasive blasting mechanism, a first clean water jetter and a second clean water jetter, wherein the first abrasive blasting mechanism, the second abrasive blasting mechanism, the first clean water jetter and the second clean water jetter are sequentially arranged in the cavity in the direction from the inlet to the outlet, and the conveying connection trigger is arranged in the horizontal direction, penetrates the cavity and drives the dangerous material container conveyed by the conveyor belt to move in the direction from the inlet to the outlet. According to the washing device for the dangerous material container, by arranging the inner wall washing assembly and the outer wall washing assembly, an original single-station washing procedure is changed into a multi-station washing procedure, the dangerous material container can be cleaned thoroughly, existing of dead corners is avoided, and the instantaneous load of the device is reduced.