Rail transit optical cable integrated bridge frame and method for laying line by using bridge frame

The invention relates to a rail transit cable laying device and a method for laying a cable by using the device. The laying device comprises multiple bridge frame columns, optical cable brackets, bridge frame partition plates, bridge frame cover plates. Holes are prefabricated in the bridge frame columns, the bridge frame columns can be fixedly installed on a building facade by expansion bolts, holes are prefabricated in optical cable brackets, one end of each of the optical cable brackets is vertically and fixedly connected to a bridge frame column through a fixed connection mode, a contact mounting surface is reserved on a free end, holes corresponding to the prefabricated holes of the optical cable brackets are prefabricated in the bridge frame partition plates and the bridge frame partition plates can be fixedly installed on the optical cable brackets through the holes, and the bridge frame cover plates are rectangular plates and can be fixedly connected to optical cable prefabricated contact mounting sur