The invention provides a multifunctional air-conditioner shell tool, and relates to the field of bullet train air-conditioner manufacturing. The multifunctional air-conditioner shell tool comprises abase frame, a rotating device and a fixing assembly; the base frame comprises lifting frames and a stretchable frame, the two ends of the stretchable frame are connected with the lifting frames respectively, a movable piece for moving the base frame is arranged on the side, away from the lifting frames, of the stretchable frame, the rotating device comprises a rotating table, and the rotating table is arranged on the lifting frame and can get close or get away from the stretchable frame; the fixing assembly is used for being connected with a fixing workpiece and can be fixedly connected with workpieces of different sizes through stretching and retracting of the stretchable frame, and the fixing assembly and the rotating table are connected and can rotate along with the rotating table. According to the multifunctional air-conditioner shell tool, the machining flowing time is shortened, the quality of a machined air-conditioner shell can be ensured, the human cost can be controlled conveniently, and the whole tool has quite high practicability.