The invention belongs to the technical field of power equipment and discloses an insulation horizontal ladder for live working of a 500kV strain tower. The insulation horizontal ladder is composed ofa wire section, a fixed section and a middle section, wherein the wire section is provided with a wire erecting fixing frame, the fixing section is provided with a support fixing base, an insulation rope connecting frame is also arranged in the wire section, the fixed section or the middle section, the wire section, the middle section and the fixed section are connected through bolt fixing hoops,the bolt fixing hoop is composed of a fixing hoop body, a fixing hoop liner and a bolt connected with the fixing hoop body. The insulation horizontal ladder is formed by assembling a plurality of sections of insulation ladders with different lengths, is convenient to carry, is particularly suitable for high mountain or long-distance erection and use, can be adjusted and assembled according to requirements of different tower types in use, and can meet use requirements of most occasions; during erection, the ladder is vertically erected, so the longitudinal stability of the insulation horizontalladder can be improved, and left and right balance can be controlled by utilizing left and right stormy waves.