Wheel is an important part of the vehicle, the wheel tread profile of the online realtime detection is of great significance. To realize the noncontact online measurement, automatic detection scheme based on image processing can measure wheel tread profile and geometric parameters timely and accurately. The laser irradiate the wheel, there is a band on the tread of the wheel. It is the wheel tread profile. Through analyzing the image taken by CCD, it can achieve the line and curve information in the tread profile with image processing and Hough transform. Some steps are proposed to improve the method, including image proprocessing、edge detection and clustering storage algorithm. To analyzing the method, taking experiments compare with traditional method. The result proves the method in this paper can detect the wheel tread profile and geometric parameter accurately and effectively.