Aimed at the complexity of the traffic natural scene,this paper put forward a kind of triangle traffic sign detection method in the basis of Radon transform.the process of detection consists of three parts.Firstly,the parts of background in image is filtered by the color characteristics of triangle traffic sign.then target image is transformed from two- dimensional European space to Radon projection space.finally,triangle traffic signs in image are extracted according to characteristics of triangle in Radon projection space.