Ordinary mortar often produces thermal deformation and cracks when it is applied. However, the low thermal conductivity of the existing phase change mortar easily leads to insufficient phase change and low energy storage efficiency, resulting in low thermal adaptability. Thus, it cannot effectively control the development of deformation, stress and fracture induced by temperature change. In this paper, paraffin-based phase change materials are used to prepare energy storage mortar, and by optimizing the three-dimensional microscopic parameters such as the specific surface area and thickness of the thermal conductivity enhancer, the focus is on improving the thermal conductivity of the phase change matrix and the energy storage rate of the phase change mortar, thereby improving its thermal adaptability. A thermal test platform was built to test its thermal performance including the energy storage and the thermal strain development with time. It is concluded that when the phase change matrix material was mixed with 30%, the surface temperature of the mortar block was lower by 9.7 ℃ than that of the ordinary mortar block, and the thermal strain was reduced by 27.54%, indicating that the phase change material improved the heat storage efficiency and significantly improved its thermal properties of self-controlled temperature.