Abstract: The ultrasonic testing method of nickel-fiberglass composite layers on the leading edge of helicopter blades was studied. The defect characteristic and defect recognition method of cladding layer of nickel-fiberglass were analyzed. For the detection requirement of thin-walled curved components,scan imaging tests for the leading edge of curved blades were accomplished by adopting the portable ultrasonic feature scan imaging method and the contact focus method. High-accuracy display and evaluation of defects was achieved by utilizing ultrasonic feature scan imaging system for the full wave column acquisition of detection signal, as well as analyzing and processing the composite layer debonding defect with the modes (e.g. amplitude characteristic and frequency analysis).