The invention discloses a building supporting device. The building supporting device comprises a supporting main body; the top end of the supporting main body is internally provided with a telescopicmain supporting mechanism; the outer side wall of the supporting main body is provided with a telescopic auxiliary supporting mechanism; the supporting main body is internally provided with a power mechanism for driving the main supporting mechanism and the auxiliary supporting mechanism to expand and contract; the outer side wall of the supporting main body is provided with a tilt sensor, the bottom end of the supporting main body is fixedly provided with a range sensor, and the outer side wall of the supporting main body is provided with a controller; and the power mechanism, the tilt sensorand the range sensor are all electrically connected to the controller. The building supporting device is easy to set up, capable of accelerating the construction progress, good in supporting effect and capable of ensuring the construction quality.