The invention relates to a sand casting detachable sand box which comprises a base plate, a front side plate, a back side plate, a left side plate, a right side plate and cleaning units. The front andback ends of the base plate are connected with the front side plate and the back side plate in a hinged mode, the left and right ends of the base plate are connected with the left side plate and theright side plate in a hinged mode, and the cleaning units are installed at the outer ends of the left and right side plates and the front and back side plates. Due to the openable design of the sand box, after casting is completed, casting parts can be directly taken out by opening the sand box, discharging can be performed with no need of turning over the heavy sand box, the casting parts can bedischarged through manual work, and no mechanical assistance is needed; meanwhile, by arranging a clamping and locking mechanism, sealing treatment needed when the detachable sand box is closed is completed, and meanwhile, due to adjustable cleaning brushes, the inner surface of the sand box obtained after discharging can be cleaned.