Cement-based decorative mortar has a natural and unique decorative effect, is breathable and crack-resistant, has good weather resistance, and can be processed into various styles of textured surfaces. It not only protects buildings but also beautifies their appearance. The project team has long been engaged in the fundamental theory and application research of cement-based materials, and has developed cement-based decorative mortar with comprehensive performance that meets the standards for use under standard conditions. They have also obtained corresponding construction methods, hold two directly related authorized invention patents, and have solved the problem of whitewashing in colored cement-based decorative mortar. The key technology proposed on this basis has cleared the main obstacle to the promotion and application of cement-based decorative mortar in climatic regions close to standard conditions. However, at the same time, research found that environmental temperature and humidity have a significant impact on the whitening of cement-based decorative mortar. Cement-based decorative mortar with excellent performance under standard conditions cannot fully adapt to areas with variable climates. Therefore, determining the whitening conditions under different climatic conditions and their control methods is a prerequisite for preparing cement-based decorative mortar suitable for regions with variable climates. To this end, this project has investigated the changes in performance and mechanisms of cement-based decorative mortar whitening under different temperatures and humidity, and developed a cement-based decorative mortar that can be promoted and applied all year round. Based on preliminary work, research was conducted on the occurrence, mechanism, and suppression methods of whitening under different climatic conditions (mainly changing temperature and humidity), proposing the mechanisms of how different temperatures and humidities affect the performance of cement-based decorative mortar, and obtaining the optimal cement-based decorative mortar with comprehensive properties such as anti-whitening ability and its preparation technology under different temperature and humidity conditions. The project team has completed the product pilot production, laying the foundation for the promotion and application of cement-based decorative mortar all year round.