The invention provides a heat treatment method of a spiral bevel gear of a cargo truck on double-row rare earth carburization equipment, and relates to a carburization heat treatment technological process of the spiral bevel gear of the cargo truck. The invention solves the problems that energy consumption of carburization heat treatment is high, production cost of a product is high and carburization quenching and gear thermal distortion still exist in a carburization process. The method provided by the invention comprises the following steps of: taking a preheating zone as a strong leakage region 1 and taking a carburizing region as a strong leakage region 2, namely taking a region II and a region III as a carburizing speed main control region and taking a region IV and a region V as a metallographic structure main control region, carrying out temperature control in the regions I, II, III, IV and V, carrying out carbon potential control in the regions II, III, IV and V, and inputtingcarburizing medium propane gas, rare earth methanol penetrating agent, nitrogen, methanol and air into a furnace, thus the heat treatment method is realized. The metallographic structure and surface hardness of the spiral bevel gear subjected to the heat treatment method provided by the invention are all optimized, and heat treatment quality of the spiral bevel gear is improved; meanwhile, capacity is improved by 23%, heat treatment production cost is reduced by 18.9%, and pollution of exhaust emission to the environment is reduced.