The invention relates to the technical field of cleaning of box-type non-negative pressure water supply devices, in particular to a box-type non-negative pressure water supply device with a function of cleaning internal stains. The box-type non-negative pressure water supply device comprises a box-type non-negative pressure water supply device body, a first groove is formed in the upper wall surface in a closed water tank of the box-type non-negative pressure water supply device body, and a first driving supporting rack is mounted in the first groove; a first electric push rod is mounted on the lower wall surface of the first driving supporting rack, a first rectangular block is fixed to the lower wall surface of the first electric push rod, and corresponding first rectangular opening grooves are formed in two wall surfaces of the first rectangular block; a second driving supporting rack is fixed in the first rectangular opening grooves, and second electric push rods are mounted on the side wall surfaces of the second driving supporting rack. The device effectively cleans stains in the water tank, does not need manual cleaning, saves time and labor, meanwhile improves the quality of water poured into the closed water tank and lets people securely use the water.