The invention discloses a vacuum auxiliary infusion forming process method of an insert formed product and belongs to the technical field of composite forming processes. According to the technical scheme, a different-material insert is provided and inlaid into a fiber fabric, and a preformed body is manufactured; a rigid plate mold is provided, the preformed body is tiled on the rigid plate mold, and a process cover plate is capped on the preformed body; the preformed body covered with the process cover plate is paved with stripping cloth, release cloth, a diversion net, a glue injection pipeline, a one-way breathable fabric, a suction pipeline and a vacuum bag in sequence, then vacuuming is conducted, resin is injected, when the preformed body is completed soaked with the resin, resin injection is stopped, and heating curing is conducted; and mold release and machining are conducted, and the insert formed product is obtained. Compared with different-material inserts which are made from sandwich structure composites and mounted through traditional process methods, the insert formed product prepared through the method has the advantages of being large in bonding area and high in bonding strength with composite skins.