Cold and hot composite forming process for complex curved surface three-dimensional flow blade of centrifugal fan

The invention relates to a cold and hot composite forming process for a complex curved surface three-dimensional flow blade of a centrifugal fan, and solves the technical problems that an existing forming process for the complex curved surface three-dimensional flow blade of the centrifugal fan is high in mold specificity and poor in mold reusability, and the blade is prone to rebound during plastic deformation. The process comprises the following steps: S1) preparation before forming; s2, the three-dimensional flow blade blank is placed in a multi-point forming die, and the upper surface and the lower surface of the three-dimensional flow blade blank are each provided with a cold pressing base plate as a liner; performing cold pressing by adopting a press machine; s3) heating the three-dimensional flow blade blank; s4, the three-dimensional flow blade blank is placed in a multi-point forming die, and the upper surface and the lower surface of the three-dimensional flow blade blank are each provided with a ho