Abstract: For the overall prefabricated insulation joint of high-voltage cables with a specific outer shield structure, the influence of mistakenly using insulating tape instead of semiconductive tape in the outer shield winding process on the electrical performance was studied. Through theoretical analysis of the mechanism of the effect of material misapplication on the interface electric field distribution, combined with finite element simulation of the electric field characteristics under different outer shield materials, and the design of simulation experiments for verification, it was found that after the material was mistakenly replaced, the electric field intensity of the outer shield of the joint under operating voltage increased from 0kV/mm to 1.1kV/mm, the tangential electric field distortion at the interface was significant, and the partial discharge quantity reached 102pC. This process deviation will seriously deteriorate the electrical performance of the insulation joint, and strict control of the outer shield winding process is required in engineering to prevent material misapplication.