Bridge expansion device

The invention discloses a bridge telescopic device which comprises a first telescopic assembly and a second telescopic assembly, the first telescopic assembly and the second telescopic assembly are symmetrically arranged on a first bridge plate and a second bridge plate, and the first telescopic assembly and the second telescopic assembly are rotationally connected; the first telescopic assembly comprises a first supporting block, a first check block and a first telescopic piece. The first supporting block and the first check block are both movably installed on the first bridge plate. One end of the first supporting block is connected with the first stop block through a first telescopic piece; the second telescopic assembly comprises a second supporting block, a second check block and a second telescopic piece. The second supporting block and the second check block are both movably installed on the second bridge plate. One end of the second supporting block is connected with the second stop block through a se