Cable accessories are an important part of the cable, and when installed, the inside of the accessories is prone to appear defeats and is affected by electrical, temperature and stress. In this paper, a simulation model of 10 kV cable accessories with different insulation defects is built, and the impact of several typical defects on the electrical, mechanical properties, and temperature distribution characteristics of cable accessories under multi-field coupling effects is studied. The results show that the small defects have almost no effect on the temperature distribution of the cable accessories, but the stress concentration phenomenon will occur at the cable defects. The larger the modulus of the defects, the maximum stress of the cable accessories will also increase. Under the stress action, insulation defects will make the deformation of the cable accessories more serious, which results in a more severe distortion of the electric field, and the maximum electric field distortion of the composite defect is the most severe, which increases by 41.6% compared with the absence of defects. The above research could provide a theoretical reference for the insulation detection and condition evaluation of cable accessories.