This paper presents a method of infrared and visible image registration based on similar triangles matching.First,Harris corner will be extracted to constitute the triangles.Second,the search algorithm this paper proposed is be used to search the similar triangles which are the best matching and then some related the matching points are be calculated by the nature of the similar triangles.Finally registration parameters are be estimated by RANSAC algorithm.Experiments show that this method can obtain a higher registration accuracy compared with traditional method of image registration based on feature points,has better robustness,and can be used to solve the infrared and visible images registration with rigid transformation.