During major repairs of aircraft aluminum alloy thin-walled components, a large number of structural crack defects inevitably occur, and there is an urgent need to develop a fast and effective detection method. An electromagnetic ultrasonic guided wave and eddy current composite detection method based on electromagnetic ultrasound and electromagnetic eddy current technology is proposed, and experimental research on crack composite detection of thin-walled and large-area aluminum alloy plates is carried out. The influence of electromagnetic ultrasound guided wave rapid detection capability and probe characteristics is analyzed, and the effectiveness of eddy current in detecting defects in thin-walled parts is evaluated. the electromagnetic ultrasonic and eddy current composite detection method was used to conduct experimental research on the composite detection of cracks in thin-walled and large-area aluminum alloy plates, and the detection ability of thin-walled parts defects was analyzed. The experimental results show that the use of electromagnetic ultrasonic probes can achieve rapid detection and positioning of defects in large-area aluminum alloy thin-walled parts, and the electromagnetic eddy current probe can accurately detect defects on aluminum alloy flat plates, achieving comprehensive and efficient detection of crack defects. It provides technical reference for the practical application of electromagnetic ultrasonic and eddy current non-destructive testing technology in aircraft thin-walled parts.