Abstract: Organic external insulation, represented by silicone rubber material, has been widely used in power systems. However, the long-term operation of silicone rubber external insulation material inevitably leads to aging problems, resulting in a decline in hydrophobic properties, which has become a bottleneck restricting the reliable operation of power systems. Consequetly, we proposed a novel approach to improve the hydrophobic properties of aged silicone rubber material using pulsed laser lift-off technique, and investigated the mechanism of laser lift-off for removing the aged surface layer of silicone rubber shed, as well as the reasons for the improvement in hydrophobic and electrical properties. The research findings indicate that, after 10 consecutive laser ablations, namely, a removal thickness of approximately 0.10 mm, the contamination, cracks and aged layer on the surface of the shed are essentially eliminated. As a result, the contact angle can reach up to 158.75°, achieving a superhydrophobic state. Although laser ablation does not change the types of elements, it creates a micro/nano composite structure on the ablated surface, and the height of the absorption peak of hydrophilic hydroxyl groups (—OH) decreases, both of which contribute to the improvement of hydrophobic properties. Therefore, compared with the unablated insulator strings, the average dry flashover voltage and wet flashover voltage of five insulator strings after ablation increase by 22.69% and 17.39%, respectively. Pulse laser lift-off process is the result of the combined action of the internal temperature field and thermal stress field of the material.