The invention provides an insulator string replacement auxiliary device. The insulator string replacement auxiliary device comprises a fixed clamp, a center shaft, a rotary support plate and an insulator fixing plate, wherein the fixed clamp comprises an U-shaped bracket, a pressing thread rod and L-shaped pressing clamp plates; two thread through holes are symmetrically formed in the two side walls of the U-shaped bracket; the pressing thread rod is sheathed in the thread through holes; the L-shaped pressing plates are arranged at the top end of the pressing thread rod; the center shaft is fixedly arranged at the lower bottom surface of the U-shaped bracket; the rotary support plate is sheathed on the center shaft; the insulator fixing plate is arranged at both ends of the rotary support plate, and is provided with an opening type through groove; a bolt hole is formed in the outer edge near the insulator fixing plate and penetrates through the opening type through groove. The insulator string replacement auxiliary device has the advantages that the structure is simple, and the operation is convenient; in the application process, the insulator fixing plate is used for directly assisting the detachment of the old suspension type insulator and quickly positioning and assisting the installation of the new insulator, so that the working efficiency is improved, and the labor intensity of workers is decreased.