Aiming at the problems of difficult registration and long registration time of existing power equipment infrared and visible images, a registration method for power equipment infrared and visible images based on improved curvature scale space (CSS) algorithm is proposed. Firstly, the Freeman chain code difference is introduced to improve the feature point extraction accuracy of the CSS algorithm; Secondly, each feature point is assigned the main direction of the vertical distance from the point to the string, and the feature description operator is obtained using the speed up robust features (SURF) algorithm; Finally, the two-sided fast library for approximate nearest neighbors (FLANN) search matching and random sample consensus (RANSAC) method are used to obtain the correct matching point pair, and the affine transformation model parameters are obtained. The experimental results show that compared with the SURF, scale invariant feature transform (SIFT), and CSS registration methods, the improved CSS image registration method has significantly improved performance indicators and its average root mean square error (RMSE) is reduced by 77.73%, 80.32% and 7.63% and its average matching time is reduced by 30.82%, 40.12% and 10.57%, respectively. It improves the registration efficiency of the power equipment infrared and visible images.