Building top beam supporting device

The invention discloses a building top beam supporting device, relates to the field of building top beam supporting, solves the problems that when an existing building top beam supporting device is used, it is difficult to automatically clamp the two sides to set positions and guarantee that the bottom end of a top beam is supported in the middle position, and comprises a base, a lifting mechanism, a supporting mechanism, an adjusting mechanism and a relieving mechanism. The building top beam supporting device comprises a base, a lifting mechanism and an adjusting mechanism, a sleeve is fixedly connected to the base, a lifting rod is slidably connected into the sleeve in the vertical direction, the supporting mechanism comprises a supporting plate and two sets of clamping plates, and the adjusting mechanism comprises two sets of clamping blocks. The bottom end of the top beam is supported, meanwhile, the clamping plates are linked to synchronously clamp the two sides of the top beam, the clamping plates are l