Surface bughole of concrete is one of surface imperfections of concrete appearance, and the detection and evaluation of surface bugholes have always been a difficult problem. This paper established a method to detect the surface bugholes of concrete by the image analysis, and put forward the evaluation parameters of the surface bugholes. The shooting distance can affect the shooting area and the detection accuracy of the image, the method of partition shooting must be used to ensure the detection accuracy according to the size of the concrete member. Based on the image processing toolbox of MATLAB, image gray, contrast enhancement and OTSU image threshold segmentation technology are used to extract the characteristics of bugholes on the concrete surface, and the threshold value of shape characteristic coefficient to distinguish the cracks and the surface bugholes is chosen as 45. The relationship between CIB scale and the area ratio of bughole is established. The parameters of area ratio and maximum diameter of bugholes can comprehensively evaluate the surface quality of concrete. (C) 2017 Elsevier Ltd. All rights reserved.