In ultrasonic phased-array testing, most probes are rigid with fixed elements. However, when testing a cambered piece, a rigid probe cannot be used directly, but an ultrasonic chock or coupling media must be used, which adds cost and reduces the accuracy. The objective of this research was to improve the tests of cambered pieces. A flexible ultrasonic phased-array probe was developed to do the flexible phased- array testing. The key technologies in the flexible phased-array probe include the probe design and the phased-array control. A new method was developed to design the flexible probe according to the curvature of the piece and the test depth. The method includes the calculation of the element’s height (he), the relative rotation angle (ωe), the distance between the adjoining elements (de), and the element’s effective testing range. A flexible ultrasonic phased-array probe has been developed using this method. However, when testing a cambered piece, a rigid probe can not be used directly, but an ultrasonic chock or coupling media must be used, which adds cost and reduces the accuracy. The objective of this research was to improve the tests of cambered pieces. A flexible ultrasonic phased-array probe was developed to do flexible phased-array testing. The key technologies in the flexible phased-array probe include the probe design and the phased- A new method was developed to design the flexible probe according to the curvature of the piece and the test depth. The method includes the calculation of the element’s height (he), the relative rotation angle (ωe), the distance between the adjoining elements (de), and the element’s effective testing range. A flexible ultrasonic phased-array probe has been developed using this method.