Ice accretion on the insulator changes its electric field distribution, which seriously endangers security and stability of power grid. At present, the two-dimensional axisymmetric model of ice-accreted insulator is established to study the electric field. However, the effects of uneven icing, number of icicles and inclination angle of icicle on the electric field are ignored, which is inconsistent with the actual circumstance. Considering this, a three-dimensional simulation model of ice-covered insulator with applied voltage was developed in the present study. The average electric field intensity of air gap (Eav) and maximum field strength of icicle tip (E max ) were determined to characterize the influence of various factors on the electric field distortion degree. The results show that Eav is independent of icicle number but increases with the increment of icicle length and icicle inclination angle. Emax raises with the increase of icicle length, icicle number and icicle inclination angle.