The caisson is a wooden construction system that covers opera stages for rain protection and sound control. Caissons in China display a diverse range of geometric expressions, delicate manufacturing, structural behaviours, and acoustic qualities. Despite their uniqueness and patrimonial interest, very little literature is known to exist, and it lacks comprehensiveness. First, this paper attempts to compile for the first time a comprehensive list of publications on caissons. Fifteen sources are identified, among which six papers address the origin and interpretation of douba and spiral caissons. In addition, other types are here recorded, based on an original field research in Zhejiang and Shanxi provinces. Following this survey, the paper also suggests a classification for caisson types according to their geometries, construction process, and structural behaviour. This classification is further supported by the interviews with a local carpenter master who specialized in the renovation and component replacement of caissons. Considerations on carving artistries, painting, and pest control are also given eventually. As a result, this study brings forward the caisson’s diversity, fineness, and significance for the history of wood joinery construction.