<p>Suichang County, Zhejiang Province, China, boasts a complex geographical setting and a long history, housing 25 national-level traditional villages with distinct spatial morphologies. However, previous studies have primarily focused on the impact of single factors (e.g., terrain) on village spatial morphology. Drawing on cultural ecology, this study selected 25 national traditional villages in the county as subjects and developed an indicator system encompassing 11 environmental, 4 cultural, and 10 spatial morphology indicators. Using methods including spatial design network analysis and Spearman correlation analysis, this study uncovered the mechanisms through which environmental and cultural factors influence the spatial morphology of traditional villages. The results indicate that environmental and cultural elements jointly shape traditional villages’ spatial morphology through distinct pathways. Terrain geomorphology constrains the regularity of architectural clusters and the complexity of alley networks. Climatic characteristics and hydrological conditions drive alley network connectivity and affect the coefficient of variation of direction. Population and transportation elements promote the expansion of traditional villages. The proximity of ancient roads is related to alley network connectivity and betweenness, while the ancestral hall centroid deviation affects the village’s morphological base. These findings provide technical support and planning guidance for the improved protection and utilization of similar traditional village heritage in southwestern Zhejiang.</p>