Abstract: When performing TOFD zone testing on thicker workpieces, it is usually necessary to use a contrast test block for depth calibration and detection sensitivity determination. However, when the general TOFD comparison test block is used for the verification of the detection sensitivity parameter setting of thick workpieces, the verification of the A-scan depth range after the second zone, and the verification of the corresponding A-scan wave amplitude difference within the depth range of the time window, the results are not ideal. The author designed a continuous sharp-angled artificial defect comparison test block. The comparison test block, being small in shape and simple in use, is more convenient and economical to make and it can accurately cover the depth required for TOFD inspection and also cover the depth range. The A-scan amplitude difference and detection sensitivity are verified.