Abstract: In the offshore engineering ultrasonic testing, due to the complex structure, it is often necessary to carry a large number of ultrasonic testing standard and reference blocks for the instrument calibration and verification. However, the weight of the blocks is relatively heavy, so it is difficult to carry all calibration and reference blocks while on a business trip or offshore inspection. In order to solve this problem, combined with the engineering practice, a new type API block having both calibration and verification functions was designed and manufactured.