<p>A transformer in a substation is key equipment within the power system, and the performance of its insulation material is directly related to the stable operation of the entire system. The aging rate of insulating materials is a concern that cannot be ignored, as it directly affects the service life and performance stability of the equipment. To more accurately assess the aging status of transformer insulation materials, an aging characteristic analysis method based on high-frequency laser imaging is proposed. A high-frequency laser imaging model is established, and high-frequency laser imaging results of substation transformer insulation materials are acquired. The obtained high-frequency laser images are preprocessed through noise removal, geometric correction, image enhancement, and grayscale conversion. Based on the preprocessing results, complete aging state data of the transformer insulation materials are obtained and analyzed. Experimental results demonstrate that the proposed method achieves excellent denoising performance, which is beneficial for testing the performance of the transformer’s glass insulator in a substation. Under both constant temperature and ultra-low temperature conditions, the tensile strength remains stable, and impact resistance is maintained to a certain extent. The dielectric constant remains at a relatively low level, indicating good insulation performance, and the increasing trend of the dielectric loss tangent exhibits relatively stable characteristics.</p>