A resin composition, a metal-resin composite formed with the resin composition and a metal substrate and a preparation method and use thereof, and an electronic product shell using the resin composition are provided. The resin composition comprises a base resin, a modified resin and a fiber, wherein the base resin is one or two or more of a polyarylene sulfide resin, a polyether resin, and a polyester resin, and the modified resin has a melting point that is 3-24° C. higher than a glass transition temperature of the base resin.