The invention discloses an electric pole island reinforcing auxiliary device and method, and relates to the field of electric pole reinforcing and repairing. The auxiliary device comprises a supporting device, a fixed support and a fixed clamp. The supporting device comprises two parallel supporting frames. The fixed support comprises two symmetrical frame plates. The two ends of each frame plateare detachably connected with transverse rods of the supporting frames respectively. The fixed clamp comprises a pair of adjustable clamping blocks arranged in the middles of the frame plates respectively and is used for clamping and fixing the electric pole. The invention further provides an island electric pole reinforcing method with the auxiliary device. The auxiliary device and method are simple in structure and operation, convenient and safe to use and capable of conveniently and reliably eliminating electric pole island hidden hazards.