Abstract: In 2014, the Grand Canal was listed in the world heritage list. At the same time, China has taken the protection, inheritance and utilization of the Grand Canal as a national strategy. Looking at the whole area of the canal, the space of ancient towns along the canal is an important material carrier for the cultural inheritance and development of the canal, while the residential architectural space is the core composition of the space of ancient towns. In the process of development and evolution, the residential architectural space of Lu Canal ancient town has formed a typical spatial paradigm with canal cultural characteristics and canal historical and cultural characteristic elements, but it has not been systematically identified and summarized. Taking the residential building space of Lu Canal ancient town as the research object, through investigation and literature analysis, this paper analyzes the spatial form characteristics of courtyard buildings and the characteristics of roofs, walls, doors and windows in the architectural space from different scale levels of residential buildings, locates the basic characteristics of residential building space under the canal culture, and guides the practice of residential building space protection and repair. The research also integrates the canal culture into the residential architectural space, and puts forward the design guidance strategy of residential architectural space. It is expected to promote the research on the historical value of the space of Lu canal ancient town and eliminate the separated development state of canal culture and ancient town space.