Abstract: In this paper, the layered defects of carbon fiber laminated structures are studied, and the CIVA simulation and test are carried out by using ultrasonic phased array detection technology. Through the sound field and defect modeling and CIVA simulation test, the ideal detection parameters of carbon fiber laminated structure delamination defect are obtained. Through the design of simulated layered test pieces and actual test, it is shown that ultrasonic phased array can effectively detect such defects.