The invention provides a heavy tractor with a detachable weight box, which relates to a tractor. The tractor needs to be mounted with the weight box in a fully-hung case; in general, the weight box is custom-designed by a transportation unit according to actual needs; the weight box and a girder are complicated to connect and mount; and a saddle on the tractor needs to be detached. According to the invention, the heavy tractor with the detachable weight box comprises a weight box and a base which is arranged under the weight box. The heavy tractor with the detachable weight box is characterized in that the base is positioned in the middle of the bottom of the weight box in a left-right direction; the base comprises a front base and a rear base; the front base and the rear base are separated to form a saddle groove matched with an automobile saddle; a plurality of upper locating pieces for locating are arranged on the base; a plurality of lower locating pieces matched with the upper locating pieces are arranged on the frame; locating grooves, which are provided with downward openings and which are small at the upper parts and big at the lower parts, are formed in the upper locating pieces; and the upper locating pieces and the lower locating pieces are detachably connected with each other through connecting pieces after matching each other. According to the technical scheme, the complicated saddle mounting and demounting process is eliminated, the heavy tractor with the detachable weight box is convenient to mount and demount, and the tractor is convenient to remodel.