With the continuous development of architectural design concepts, the thermal cycle optimization of interior space has become an important topic to improve energy efficiency and comfort. The introduction of digital light processing (DLP) technology provides new possibilities for 3D modeling and thermal cycle analysis. This study uses digital light processing technology to design and optimize the thermal cycle of indoor space, and explores its application in real-time animation 3D modeling to provide a more intuitive visual display. DLP technology is used to build a three-dimensional model of interior space, and heat flow analysis software is combined to simulate the thermal cycle of different design schemes. The dynamic simulation method was used to analyze the change of heat circulation in the exhibition room and its influence on the indoor environment. The results show that the indoor thermal cycle optimized by DLP technology can effectively improve the heat distribution uniformity and energy efficiency utilization, and the simulation results show that the improved scheme has significant advantages in thermal comfort. This study proves the feasibility and effectiveness of digital light processing technology in indoor space thermal cycle design, and provides a new idea for future architectural design and thermal cycle management.