The painting Scenic Attractions of West Lake, collected at the Freer Museum of Art in the United States, reproduces the scene of the West Lake in Southern Song Dynasty. In the painting, there is a large number of connected roof buildings, whose quantity and uniqueness in shape are both astonishing. To explore the nature of this kind of architecture in the painting, and to restore the real appearance of the West Lake Garden in the Southern Song Dynasty, this article starts with an overview of Southern Song Dynasty garden, then deeply interprets the Scenic Attractions of West Lake, conducting a systematic research and statistics on the connected roof buildings in the painting. After that, through plane translation, it analyzes the approximate roof building plane composition in Song paintings, and deduces the formation and evolution of such roofs. By comparing the rooftop images in previous paintings, it is possible to further speculate on their origins. Finally, it searches through real-life photos and existing examples to restore the true appearance of connected roof buildings in history.