The invention discloses a portable temporary bridge for connecting a
tower crane and a building. The portable temporary bridge comprises a structural bulk stereogram of a supporting device. A temporary bridge main
keel, a temporary bridge cross rod, a front limiting hook, a rear
limiter and a
protective barrier are all of
steel structures formed by
machining plastic steel and
steel plates, the position over the temporary bridge main
keel is formed by seamlessly connecting two reinforcing meshes with the size of 2,000 mm * 1,000 mm, and the front limiting hook is arranged in front of the temporary bridge main
keel. and is welded to the middle of the front section of the main keel together with the temporary bridge main keel, the rear
limiter is arranged behind the temporary bridge main keel, and is welded to the middle lower portion of the rear section of the main keel together with the temporary bridge main keel, and the two portions above the temporary bridge main keel are both provided with protective barriers, are also steel structure components and comprise transverse rods and vertical rods. The invention further discloses a construction process of the temporary bridge main keel and the
protective barrier in the supporting device, a
welding machining process and matters needing attention among all
steel structures of the supporting device,
rust-proof treatment after weldingis completed, and material compositions of steel structural members and the
steel bar meshes.