The invention discloses a test cabin for the radon exhalation rate of a building material surface. The test cabin comprises a cabin body, wherein the cabin body is an inverted-cone-shaped cabin body, a cabin cover is arranged at the top of the cabin body, an air evening machine, a thermometer, a lamp and an air sampling hole are arranged at the bottom of the cabin cover, the thermometer, the lamp and the air sampling hole are all arranged around the air evening machine, the air sampling hole penetrates through the cabin cover, a cabin cover handle is arranged at the top of the cabin cover, an air evening machine switch is arranged on one side of the cabin cover handle, a lamp switch is arranged on the other side of the cabin cover handle, a sample is placed in the middle, even distribution of the radon concentration is guaranteed, a sample rack can be taken out of the cabin body by a sample rack handle, placement of the sample and clearing of the cabin body are facilitated, the thermometer, the lamp and a timer on the cabin cover can monitor the environment in the cabin body in real time, the accuracy of the test result is guaranteed, the cabin body and the cabin cover are connected through threads, and pouring of residual garbage in the cabin body is facilitated.