The invention discloses a composite sole, which comprises an undersole and a plurality of cloth pieces, wherein the undersole is made of rubber, plastic cement or TPR (thermoplastic rubber); the undersole is filled with a plurality of cloth pieces; and the undersole and the plurality of cloth pieces are integrally formed through injection molding. The invention also discloses a forming method of the composite sole. The composite sole provided by the invention has the advantages that the undersole is filled with the cloth pieces, so that the sole has good anti-deflexion performance during bending; meanwhile, good puncture resistance performance is provided for the sole through the cloth pieces; the service life of the sole is greatly prolonged; meanwhile, the sole is light; the manufacturing cost is also effectively reduced; when the undersole material made of transparent materials is used, the whole of the sole shows the visual effect different from the traditional sole through the cloth pieces positioned inside the sole.