Abstract: Aiming at the requirements of space-time synchronization in the process of robot automatic detection based on ACFM technology, the collaborative detection method of industrial robot and ACFM was systematically studied. The key problems such as synchronous acquisition method of position and magnetic field signal, three-dimensional magnetic field characteristic signal imaging, defect quantification and location method in the process of cooperative detection of robot and ACFM were solved consequently. A complete set of robot and ACFM collaborative detection experimental system was developed and systematically tested. The results show that the experimental system of space-time synchronization can realize surface defect detection and imaging, precise positioning and quantification of surface defect in specimens. The location synchronization accuracy is 0.5 mm, which will promote the efficiency and accuracy of ACFM detection automation.