The present invention applies to a molding method for a fiber-reinforced plastic structure having an internal cavity, in particular, for example, a vehicle wheel (10) made from fiber-reinforced plastic. Firstly, particle groups (6a), which mainly consist of a plurality of high-rigidity particles, are accommodated in bags (6), and a plurality of cores (4a-4h) are formed. A reinforcing resin substrate, such as a prepreg or textile, is placed between the plurality of adjacent cores so as to be interposed therebetween. For example, a plurality of molding base materials are prepared by surrounding each core (4a-4h) with a prepreg (3), and the plurality of molding base materials are combined and placed inside a molding die, and the molding base materials are compression molded. When compression molding, a part of the outer surface of the cores (4a-4h) is locally pressurized, and the internal pressure of the cores is increased, changing the shapes thereof, thus eliminating air gaps that are present between the cores and the prepreg and/or the prepreg and the molding surface of the die.