The invention discloses a mining dump vehicle cargo compartment damping system which comprises a cargo compartment, a frame, damping devices and a connecting shaft. The damping devices are distributedon the frame and used for bearing the cargo compartment, a first installing hole is formed in the tail portion of the frame, a second installing hole is formed in the lower side corresponding to thefirst installing hole, of the cargo compartment, the connecting shaft penetrates through the first installing hole and the second installing hole to connect the cargo compartment with the frame, and the connecting shaft suspends in the first installing hole when the cargo compartment is switched from a no-load operating condition to a full-load operating condition. The mining dump vehicle cargo compartment damping system has the advantages of avoiding frame tail portion stress concentration caused by connecting shaft stress during full load and avoiding cargo compartment sliding during no load.