This paper systematically explores the cultural connotation and spatial layout characteristics of the landscape form of Beijing's central axis based on cultural gene theory, semiotics, and spatial syntax methods. Through Pierce's semiotic ternary model (illustration, indication, symbol), it analyzes the power symbol mechanism of The Imperial Palace architectural complex, the ecological wisdom characteristics of the Beihai water conservancy system, and the symbolic expression of folklore in the marketplace space and reveals that its distribution of power presents an obvious hierarchical structure. The study reveals that the landscape of the central axis consists of the power symbol zone, the ecological wisdom zone, and the folklore symbol zone. The Power Symbol Zone, with The Imperial Palace as its core, reflects hierarchical order and cultural authority; the Ecological Wisdom Zone, which reflects the harmonious relationship between human beings and nature and technology; and the Folklore Symbol Zone, demonstrates the combination of locality, practice, and commonality. Through the spatial syntax analysis, the power symbol zone has a strong cultural radiation core, the ecological wisdom zone significantly supports the human-land interaction relationship while the folklore symbol zone faces the problem of hindered cultural revitalization mechanism. The innovation of this paper lies in the integration of cultural gene theory and semiotic analysis, and the combination of qualitative analysis and quantitative methods, which provides a new tool for cultural heritage protection with both cultural depth and technological innovation. By exploring the relationship between cultural gene decoding and spatial syntactic coupling, this study not only expands the theoretical framework of traditional Chinese urban planning but also provides new directions and technical paths for future research. Cultural genes; Semiotics; Spatial syntax; Beijing central axis