Abstract: China is a mountainous country, of which Southwest China is a typical mountainous region with a large number of mountainous historical towns and rich and diverse development types. The rapid development of urbanization in China has brought a certain degree of impact on the protection and development of historical cities and towns, resulting in the protection dilemma of destruction of landscape relations, lax plane layout, disappearance of street pattern and loss of node identification. In order to realize the orderly development of historical cities and towns in Southwest China, this study summarizes the spatial morphological characteristics of historical cities and towns in Southwest mountainous areas in terms of landscape relationship, plane layout, street and lane pattern and node identification, and continues from the landscape relationship of historical cities and towns, updates the plane layout and reshapes the street and lane pattern. This paper puts forward the protection strategy of the spatial form of historical cities and towns in the Southwest region from the four aspects of node identification and rejuvenation, so as to achieve the new goal of restoring and inheriting its spatial form, in order to provide protection strategies and method references for the orderly development of historical cities and towns in mountainous areas in the Southwest.