Aiming at the defects of porous materials such as blockage and angle gap, a method of surface defect detection for porous materials based on machine vision is designed in this study. By means of effective segmentation of target area, ambiguity detection, morphological treatment and analysis, the rapid location and feature analysis of surface defect for porous materials are realized. The experimental results show that the accuracy and efficiency of the algorithm can meet the real-time detection requirements of industrial production.