Abstract: Using 09# wax and 1,6-hexanediamine as raw materials, high melting-point wax is synthesized under the condition of normal pressure without catalyst and exchange gas, which could be used as a phase change energy storage material. The optimal reaction conditions are determined by orthogonal test design, followed by the single variable method. The mole ratio of 09# wax and 1, 6-hexanediamine is 1:0.65, and the low-temperature reaction time is 2-2.5 h at 165-175 ℃，and the high-temperature reaction time is 1.5-2.0 h at 190-195 ℃. The produced phase change wax is tested by differential scanning calorimetry(DSC). The melting enthalpy is greater than 170 J/g, and the melting point is 140-145 ℃. The enthalpy variables and melting point are higher than the current domestic similar products.