The invention discloses a forming process method of a combined type sheet metal buckling groove mould. The method is characterized by comprising the following steps: (1) a sheet metal part is positioned; (2) a right-angle mould oil cylinder stretches out to drive a right-angle mould to move vertically and downwards to press the sheet metal part tightly; (3) an upper top concave mould oil cylinder stretches out to drive the upper top concave mould to move vertically and upwards to bend the end head of the sheet metal part into a Z shape; (4) a down fold convex mould oil cylinder stretches out to drive a down fold convex mould to move vertically and downwards to bend the Z-shaped end head into a buckling groove with an angle; (5) the upper top concave mould oil cylinder and the down fold convex mould oil cylinder retract successively; (6) an inclined push mould air cylinder stretches out to drive an inclined push mould to move slantways and downwards to push the buckling groove with the angle correctly to finally form; and (7) the inclined push mould air cylinder retracts, and the step (1) is repeated. By the method, the production processing efficiency is improved while the forming processing cost of the freezer sheet metal buckling groove can be reduced, so that a good application value is achieved.