A self-cleaning drum washing machine, comprises a coaxial drum and outer tub. Cleaning particles are arranged between the drum and the outer tub. Structures between the drum and the outer tub opposite to each other are smooth. A flange is fixedly connected to the bottom of the drum; the outer portion of the flange has a smooth structure or an enclosed cavity is arranged on the outer portion of the drum bottom; the flange is arranged in the cavity; a shaft hole is arranged at the center of the cavity; and a drum shaft sticks into the cavity through the shaft hole and is connected to the flange. The smooth structures go against the attachment of dirt, so that the outer wall of the drum and the inner wall of the outer tub can be conveniently cleaned by the cleaning particles.