The invention provides a composite phase-change nano-fiber material and a preparation method thereof. The composite phase-change nano-fiber material is characterized in that a phase-change material ispolyethylene glycol, a supporting material is polyvinylpyrrolidone, a thermal conductive material is graphene oxide, and the composite phase-change nano-fiber material is prepared by an electrostaticspinning technology. The preparation method of the composite phase-change nano-fiber material comprises the following steps: 1) preparation and dissolution of the graphene oxide; 2) preparation of anelectrostatic spinning solution; 3) high-voltage electrostatic spinning. The composite phase-change nano-fiber material and the preparation method thereof provided by the invention have the benefitsthat the composite phase-change nano-fiber material containing the polyethylene glycol and the graphene oxide is prepared by utilizing the electrostatic spinning technology; the process is simple, process parameters are easy to adjust, and thermal conductivity coefficients of the composite phase-change material are improved; the leakage of the phase-change material in the solid-liquid phase-changeprocess is effectively prevented.