In order to solve the problems of poor accuracy and low efficiency in manual detection of foreign matters in the internal and external wall groove of zirconium tube，a visual detection method based on the average template is proposed in the paper. In this method，compound light source is used to image the conical surface of the groove on the inner and outer walls of zirconium tube，and the obtained image is unfolded into rectangle image.Based on the threshold setting，the similarity comparison and replacement of the gray value of the column pixels are carried out，and then the average template of the groove without foreign matters is designed. The suspected foreign matters are located by the difference detection between the template and the real image. Finally，the foreign matters are identified according to the actual criterion rules. Experimental test and enterprise application show that the method can effectively detect the small size foreign matters in the groove of zirconium tube，with an accuracy of 99.6%，and an detection efficiency of 1.84 s/piece，and the corresponding equipment runs well in the enterprise.