Village planning has assigned a single fixed boundary to the village to protect the external spatial form type of the village from destruction. To meet its development needs, the village needs to change the fixed boundary. How to delineate a boundary that does not destroy the external spatial form type of the village but also meets the development needs of the village has become an urgent problem to be solved. This paper proposes a strategy to delineate flexible boundaries for villages. This strategy accomplishes the delineation of flexible boundaries without destroying the spatial form type of the village by adjusting the control parameters to meet the needs of village development for boundaries. Firstly, the strategy calculates the value of the optimal village boundary corresponding to the control parameter, then constructs the mathematical and theoretical relationship between the village’s external spatial form type and the optimal boundary corresponding to the parameter, and finally determines the range of spatial form type corresponding to the control parameter and selects 20 traditional villages in China as empirical evidence. The results show that: the length of control parameters corresponding to the external spatial form types of villages shows the law of segmental distribution; the higher the degree of banding of the external spatial form of villages, the greater the length of control parameters; the range of control parameters for clustered boundary delineation of the village, and the banding tendency of the clustered and banding spatial form types is 15-30, 30-50, and 50-130. The results can provide theoretical references for the planning and design of villages, as well as provide decision-making help for the village participants.