The invention discloses a heat-storage and thermo-regulated fiber. A comb-shaped polymer phase change material is used as the component A and a fiber-forming polymer is used as the component B to prepare the heat-storage and thermo-regulated fiber by the composite melt spinning method, wherein the comb-shaped polymer phase change material is the homopolymer of poly(3-alkylthiophene), the copolymer of two kinds of 3-alkylthiophenes in the molar ratio of 20:80-80:20, or the mixture of two kinds of poly(3-alkylthiophene) homopolymers in a mixing weight ratio of 20:80-80:20; the fiber-forming polymer contains at least one of copolyacrylonitrile, copolyester, copolyamide, polypropylene and polyamide; and the weight percentages of the component A and the component B in the fiber are separately 20-60% and 80-40%. The fiber has not only good heat-storage and thermo-regulated performance, but also the characteristics of antistatic property, low leakage, good thermal stability and the like.