The invention relates to a method for detaching a wall-attached pull rod of a tower crane by virtue of a suspension bridge. The method comprises the following steps: (A) firstly producing a suspension bridge platform, and mounting the suspension bridge platform on the lower part of a jacking sleeve frame of the tower crane; (B) transferring the suspension bridge platform down to the lower part of a wall-attached frame, fixedly connecting one end of the suspension bridge platform to a main chord of a standard node by virtue of two M24 high-strength bolts; (C) lifting up one end of the suspension bridge to form a 90-degree angle with the standard node, and locking a steel wire rope; (D) unfolding a folded platform, and fixing the steel wire rope at a tip to one side of the sleeve frame; (E) detaching the wall-attached pull rod of the tower crane by a detaching worker standing on the suspension bridge platform; and (F) after an attached wall is detached, packing up the folded platform, lifting the suspension bridge platform to be parallel with a tower body, and loosening the suspension bridge platform and a tower crane standard node adjusting bolt to enable the suspension bridge platform to fall along the descending of the sleeve frame of the tower crane. The method has the advantages of simplicity, convenience in use, no occupied space and high safety performance.