The utility model relates to a simple and easy telescoping device of steel construction passenger footbridge, in the same direction as connecing part, transition subtotal passenger footbridge part inthe building that sets gradually in the plane, leave the expansion joint between part and the passenger footbridge part in the same direction as connecing in the building, the transition part is including the steel sheet, one of them end position of steel sheet in the same direction as in connecing partial upper end recess, is fixed through a plurality of bolted connection between the part in thesame direction as connecing in steel sheet and the building in the building, the other end of steel sheet is located passenger footbridge's upper end recess, fill the elastomer filler material betweensteel sheet and the passenger footbridge recess lateral wall. This structure simple structure, the construction is simple and convenient, and the cost is low, little to connecting building floor destruction, need not on a large scale, the chisel removes the floor concrete.