Device and method for laying power cable on building wall

The invention discloses a laying device for a power cable on a building wall. The laying device comprises a lifter, a fixing structure, a plurality of steel wire tractors, a plurality of lifting structures and a plurality of steel wires. The fixing structure is located above the lifter, and a first guide hole is formed in the bottom end of the fixing structure; the multiple steel wire tractors are sequentially arranged in the horizontal direction, the multiple lifting structures are arranged below the multiple steel wire tractors in a one-to-one correspondence mode, each lifting structure comprises a fixed sliding groove plate, a sliding plate and a cable support, and the sliding plates are slidably clamped to the fixed sliding groove plates in the vertical direction; the cable bracket is arranged on the sliding plate; the lifter drives the sliding plate and the cable support to slide up and down relative to the fixed sliding groove plate through the fixing structure, the steel wire tractor and the steel wire