The expansion device of Railway Bridge is an important connecting part between the beam ends of Railway Bridge. It plays an important role in the expansion joint and waterproof performance at the end of the bridge. Its quality and waterproof performance will directly affect the durability of the whole bridge. The durability of railway bridges on passenger dedicated lines is highly required. Reliable and durable waterproof expansion devices must be used between beam joints to protect the beam body and bridge substructure. The expansion device is applicable to common span bridges, ballasted and ballastless track structure bridges of passenger dedicated lines with speeds of 350 km / h and 250 KM/h.