Abstract: Resin infusion process is a common technique for large-scale resin-based composite materials. Due to the complex process, and many influencing factors and manual operations in the resin infusion process, the detection and identification of defects are particularly important. In the study, the common flaws of resin infusion are designed and prefabricated, and then are detected and analyzed qualitatively and quantitatively by using phased array ultrasonic equipment.Resultsshow that the phased array ultrasonic equipment can effectively identify the flaws and quantitatively analysis their depths and sizes. Different flaws have different characteristics of A-scan and S-scan signals.