Cross⁃linked microcapsules were prepared by suspension polymerization with polystyrene as the wall material and 58# paraffin as the core material. The effects of polymerization temperature, initiator dosage, crosslinker type and core⁃wall ratio on microcapsules were investigated. The structure, morphology, heat storage performance and thermal stability of microcapsules were characterized by FT⁃IR, SEM, DSC and TG. The experimental results show that the microcapsules prepared by the polymerization temperature of 80 ℃ and the initiator AIBN 2% have good spherical shape. The microcapsules prepared by the cross⁃linking agent DVB have less clastic debris, no agglomeration and good thermal stability. The microcapsules prepared by the core wall ratio of 3∶1 have a phase transition enthalpy of 152.2 J/g, a core material content of 82.2%, and the best heat storage performance.