The present application provides a preparation method for a core-shell structured tungsten/gadolinium oxide functional fiber for X and γ ray protection, comprising: first preparing a core-shell structured tungsten/gadolinium oxide powder; preparing a W@Gd2O3/PP blended melt from the powder; and preparing a W@Gd2O3/PP composite fiber from the blended melt. The core-shell structured tungsten/gadolinium oxide functional fiber prepared by the method can play a role in synergistic protection in the aspect of radiation protection, eliminate a weak protection area, and effectively absorb secondary radiation generated by radiation. Secondly, the prepared functional fiber has the characteristics of no lead and light weight, and has good application prospects in the aspect of X and γ ray radiation protection.