The invention discloses a pneumatic mold removing machine of a lateral mold. The pneumatic mold removing machine comprises a main frame, a propelling air cylinder, an oil pressure buffer, a rail, a hook air cylinder, a first jacking air cylinder, an overturning frame, a second jacking air cylinder, a propelling frame, an overturning air cylinder, an adjusting sleeve, an air cylinder connector, a rear supporting wheel set and a front supporting wheel set. The pneumatic mold removing machine of the lateral mold is compact and reasonable in structure; all the parts can be adjusted aiming at the structure of a plaster mold; the running is more stable through throttle valves of the air cylinders; mold removing and overturning processes can be finished by only one person and common female workers can operate, so that the labor intensity of the workers is alleviated and the production cost is saved; the propelling air cylinder is arranged so that the propelling frame can be effectively driven to move frontward and backward through the stretching and retracting of the air cylinders and the aim of removing the lateral mold is realized; the overturning air cylinder is arranged so that the overturning frame can effectively do turning-up and falling-off actions through the stretching and retracting of the overturning air cylinder.