Smoke prevention and exhaust device for building

The utility model discloses a smoke prevention and exhaust device for a building, which belongs to the technical field of smoke prevention and exhaust devices and comprises a smoke prevention and exhaust machine body, an adjusting and mounting assembly is fixedly mounted on the outer side of the smoke prevention and exhaust machine body and comprises a fixing frame, a threaded cylinder, a threaded rod and a fixing rod, fixing frames are fixedly connected to the two sides of the outer side of the smoke prevention and exhaust machine body in a sleeved mode, threaded cylinders are rotationally connected to the middles of the top ends of the fixing frames, threaded rods are connected to the inner sides of the threaded cylinders in a threaded mode, fixing rods are fixedly installed at the top ends of the threaded rods, and the positions of the fixing rods can be adjusted. And a worker can conveniently adjust and fix the position of the fixing rod, the difficulty of positioning the fixing rod by the worker is reduc