As a supporting surface and interface for separating spaces in buildings, wall is one of the eye-catching places, and its decorative effects directly affect the atmosphere of the space, thus receiving increasing attention from architectural designers. Based on the design principles of wall decoration, with the survey results of satisfaction with the original wall painting by experts and scholars in the art field and residents of M village as supporting conditions, the painting art wall was designed and optimized in combination with the artistic and functional aspects of architectural design, which aims at studying the connotation of the artistic expression of wall decoration in architectural design. Through the analysis of the case study on the optimization design of wall painting in M Village, the results showed that 83.5% of villagers believe that wall art painting has a highly decorative effect. Architectural decorative wall painting design is conducive to expressing emotions, showcasing personalized art, and disseminating cultural ideas, thereby stimulating villagers' pursuit of artistic beauty and enhancing the taste of rural life.