Abstract: In recent years, extreme heat events have occurred frequently, with a surge in load-side electricity demand and insufficient supply capacity on the power-side. In this context, a planning study is conducted on commercial complex buildings to guarantee reliable supply of loads under extreme heat events. First, the impact of extreme high temperature events is modeled and the important load reliable supply set is divided. At the same time, a price-based demand response is established to change the load curve, and a incentive-based demand response is superimposed to further reduce the load level under extreme high temperature events. The impact of economic and psychological factors on the response probability of its users is considered, and its uncertainty is characterized. Secondly, with the objective of optimizing the annual total planning cost in the planning cycle of the building, a planning model for reliable supply of loads under extreme high temperature events in the building is developed for each energy equipment model and number of units in the decision-making building. Then, a distributionally robust optimization model using integrated paradigms to constrain the probability distribution of ordinary scenarios and Boolean variables to constrain the probability distribution of extreme heat scenarios is applied to cope with the uncertainty of accessing distributed photovoltaic, photovoltaic curtain wall and loads on rooftops. Finally, an arithmetic example shows that the proposed model has good economy and robustness in guaranteeing the reliable supply of loads under extreme events. The research results can provide some reference for building integrated energy planning.