The surface defect detection of bridge cable about the safety and healthy of the bridge is studied in the paper.In view of the drawback of two detecting methods for surface covering layer of cable,the scanning acquisition system and the fault detection system in the core of embedded DSP were designed,which included image acquisition part,DSP hardware platform,creeping moving part and fault location part.Furthermore,a fast measuring method based on image processing of the cable surface corrosion and damage was proposed,which included image interception,filter denoise,image segmentation and defect recognition.The experimental result shows that it can detect the cable surface defect in real time,and its performance index is that minimal recognition area is 1cm²and real-time image processing speed is 10cm/3s.