Abstract: As a key link in the safe operation of power grids, cable joints has become the main cause of cable faults due to interface discharge problems. The traditional artificial coating process of silicone grease is base d on experience, which leads to uneven coating, excessive coating or impurity mixing, and increases the risk of electric field distortion and partial discharge. In order to solve this problem, an automatic coating device for cable heads silicone paste is designed in this paper. The device controls the flow of silicone grease through a fluid channel and a a regulating valve. The material is evenly compressed by a compression assembly, which is combined with a removable coating section to accommodate different cable sizes and ensure a precise and controlled coating range. The device adopts corrosion-resistant material and a wear-resistant silicone sealing structure to support rapid cleaning and reuse, effectively avoiding the random defects of manual operation. The device can improve the uniformity and consistency of silicone grease coating, reduce the interface defects, prolong the service life of cable bridge and provide technical support to improve the reliability of distribution network operation.