The invention relates to phase-change energy-storage microcapsules and a preparation method thereof; the phase-change energy-storage microcapsules are prepared from a core material, a wall material, an emulsifier, an initiator and deionized water; the core material is fatty acid ester, the wall material comprises methyl methacrylate and pentaerythritol tetraacrylate, the emulsifier is formed by mixing a nonionic surfactant and an ionic surfactant with the ratio of 1 to 1, the initiator is benzoyl peroxide, the mass ratio of the core material to the wall material is 1:1-1:4, the content of the emulsifier is 5-10% of the total mass of the core material and the wall material, the content of the initiator is 2-5% of the mass of the wall material, and the ratio of the total mass of the core material and the wall material to the mass of the deionized water is 1:4-1:6; a low-cost fatty acid ester is used as a phase change material, a mixture of the ionic surfactant and the nonionic surfactant is used as the emulsifier, a capsule wall is formed through cross-linking polymerization with combination of a suspension polymerization technology, and the phase-change microcapsules with smooth surface, uniform particles and high phase change material content are obtained.