Thinned carcass ply part used in radial tire

The invention discloses a thinned carcass ply part used in a radial tire, including a carcass ply framework and a rubber overlying layer, the framework material being synthetic fiber ply material including nylon ply or polyester ply, the number of the ply being a single layer or a plurality of layers, and the rubber overlying layer is made of natural rubber or a mixture of natural rubber and synthetic rubber. According to radial tire carcass ply production technology, cord expansion, rolling and rubber applying are carried out to produce a standard-width thinned carcass ply sheet with the thickness of the rubber layer being 3-10% thinner than that of sheet made through traditional process, and then radiation prevulcanization processing is carried out on the thinned carcass ply sheet by adopting an electron accelerator irradiation device to prepare a thinned carcass ply part. The thinned carcass ply part used in a radial tire of the invention, provided with a thinned carcass ply structure, has the advantages o