The present disclosure relates to a fixing device for repairing an aluminum alloy wheel hub, comprising a base (1), a support plate (4), first hydraulic cylinders (3); a bottom plate (5) slidably mounted on the support plate (4); a fixing plate (9); pressing plates (12); adjusting bolts (13); two sets of guide rollers (15) rotationally mounted in a groove (14); a bracket (17) rotationally mounted at the position, located on one side of the fixing plate (9), above the support plate (4) ; a top plate (18) fixedly mounted at the top of the bracket (17); a push plate (20) connected with the bottom of the top plate (18) through a second hydraulic cylinder (19).