The invention belongs to the technical field of coal mine underground auxiliary trackless transport equipment, in particular relates to a horizontal dumping device of a rubber-tired vehicle for a thin seam mine, and solves the problem of incapability of guaranteeing tip-back dumping of a compartment due to small underground lane space. The horizontal dumping device of the rubber-tired vehicle for the thin seam mine comprises a dumping mechanical device and a horizontal dumping hydraulic system, wherein the dumping mechanical device comprises a compartment, a pseudo-bottom capable of moving in the compartment, and a push plate capable of moving on the pseudo-bottom; the horizontal dumping hydraulic system comprises pseudo-bottom oil cylinders fixed at the two sides of a baseplate of the compartment; the pseudo-bottom oil cylinders are connected with the back end of the pseudo-bottom through piston rods; and push plate oil cylinders fixed at two side walls of the pseudo-bottom are additionally arranged, and are connected with the back end of the push plate through piston rods.