The characteristics of the GQF-C type telescopic device: the building height is low, the height of the overall shaped steel is only 50mm, the structure is simple, the installation is convenient, and it has obvious reliability, comfort and durability. It is suitable for all kinds of bridges with deck pavement thickness ≥ 80mm and expansion amount ≤ 80mm. It is not only convenient to replace the expansion device of the old bridge, but also can be selected for the construction of the new bridge.