Drainage structure for building

The invention provides a drainage structure for a building. The drainage structure for a building comprises an inspection chamber and a water seal chamber, wherein the water seal chamber communicateswith the inspection chamber, a partition piece is arranged between the inspection chamber and the water seal chamber, the water seal chamber communicates with the inspection chamber from the top of the partition piece, a first water inlet channel is formed in the inner wall of the water seal chamber, and the height of the partition piece is smaller than or equal to that of the first water inlet channel; and a drainage pipe is arranged in the first water inlet channel, a water outlet of the drainage pipe is located in the water seal chamber, and the height from the water outlet to the bottom ofthe water seal chamber is smaller than that from the tail end of the partition piece to the water seal chamber. According to the invention, a water seal well and an inspection well are integrally arranged, so that the occupied space of the water seal well and an inspection well is reduced, more space can be provided for other facilities (such as basements and outdoor pipe networks) of buildings,and the construction convenience is improved.