Machining machine and machining method for metal casting after casting forming

The invention provides a machining machine and a machining method for a metal casting after casting forming. The machining machine comprises a mounting bottom plate, supporting legs, a supporting plate, a supporting disc, a lifting mechanism, a positioning mechanism and a cutting mechanism. According to the machining machine and the machining method for the metal casting after casting forming, the problems that when the metal casting is cut off after being formed, multiple persons are needed to cooperatively position and cut off the metal casting, the labor intensity of workers is increased due to a large amount of repeated operation, the cutting-off operation of the casting in batches is difficult to carry out, the operation efficiency is low, the multi-station clamping operation is difficult to carry out on the metal casting, the influence of mechanical vibration on the mechanical casting during the subsequent cutting operation is increased, the flatness of the cut-off surface is reduced, the multi-directio