The energy consumption of the container that has no energy storage enclosure is large and its indoor temperature fluctuates greatly. The traditional enclosure design method cannot effectively maintain the indoor temperature in a comfortable temperature range. Application of phase change energy storage technology in the design of retaining structure of the container building can greatly improve its thermal performance and effectively adjust indoor temperature fluctuations. Taking the microcapsule phase change material as an example, the influence of parameters such as building internal disturbance and phase change layer design on temperature regulation performance was studied by using Design Builder software simulation analysis method. After analyzing the adaptive design method of phase change materials in the composite enclosure structure of container box, it is found that the phase change composite wall with 30 mm thick and phase change point of 29 ℃ can effectively improve the thermal comfort of the building in the summer. In addition, the optimal design method of phase change composite retaining structure and its influence on indoor thermal comfort are obtained. This study provides the theoretical support for the application of phase change materials in container building design and evaluation.