Telescopic assembly type high-speed railway bridge and assembly method thereof

The invention discloses a telescopic assembly type high-speed railway bridge and an assembly method thereof. The telescopic assembly type high-speed railway bridge comprises a frame plate (1), a built-in movable plate (14), a left side plate (3), a right side plate (4), an abutting piece (6), a length adjusting assembly, a left side assembly assembly and a right side assembly assembly. The left side plate and the right side plate are arranged at the edges of the frame plates, the left side assembling assemblies are arranged on the left side plate, the right side assembling assemblies are arranged on the right side plate, and the left side assembling assemblies and the right side assembling assemblies are detachably connected, so that the two frame plates are transversely assembled; the pair of built-in movable plates is embedded in the frame plates in a sliding mode through the length adjusting assemblies, the two abutting pieces are arranged at one end of one built-in movable plate and the other end of the o