UHPC bridge expansion device with adjustable height

The invention relates to the technical field of bridges, in particular to a height-adjustable UHPC bridge expansion device which comprises a bearing support and a concrete layer, the bearing support is integrally composed of a connecting transverse frame, a bearing support, a center truss, a supporting support and an extending support, and the bearing support is provided with a first supporting mechanism used for supporting the concrete layer through a driving worm. The bearing support is provided with a second supporting mechanism used for supporting the concrete layer through a ball screw. The connecting transverse frame, the bearing support, the center truss, the corresponding support and the extending support form the bearing support, so that a concrete layer can be movably supported on the bearing support; a supporting effect is provided for the concrete layer from the two side positions; the ball screw integrally connected with the driving worm is arranged, and the lifting nut moving up and down is arra