A provided main-shaft clamping apparatus is shaped of a combined shape of a cuboid structure and a cylinder structure, and is prepared from an aluminium material. The main-shaft clamping apparatus comprises a circular hole, a main-shaft placing hole and a screwed hole. The main-shaft clamping apparatus has the advantages of being increased in bearing force and rigidity, making machinery relatively stable during processing, improving stability of the machinery, guaranteeing product processing precision and the like.