The invention is a method of erecting all-
cantilever erected steel truss beams assisted by
diagonal ropes, as well as a relevant
system. The method utilizes a bearer cable
tower combined with a steel structure center
tower column with
diagonal ropes; install a
tower-type crane on the top face of the steel truss beam end at the first hole with an overhead bridge crane in a ground craning
station; anchor cases below the front and rear
diagonal ropes are connected with side plates at steel beam nodes, and after that, directly lift the tower to apply pre-tension on the diagonal ropes; perform all-
cantilever erection for the front steel truss beam. After finishing erection of the orifice steel beam, complet load removal from the diagonal ropes with a method of pushing up the temporary seat for the front
pier and lowering back a pushing and craning device between upper and lower seats of the bearer cable tower. The
system comprises an auxiliary tower truss, a tower center vertical column, the upper and lower support seats, the front and rear diagonal ropes, the upper and lower anchor cases for diagonal ropes, a tower top anchor beam and a walking mechanism. The invention has the following advantages: For large-span continuous steel truss beams, utilize a special device additionally to erect multi-span steel truss beams, so as to reduce
internal stress in installation of steel truss beam members, lower end deflection of the front extension arm, and increase the inclination stability of a steel truss beam on the extension arm. Meanwhile, the invention can low investment and short construction period and provide very convenient operation.