Ultrasonic detection method for seal weld of nuclear reactor control rod driving mechanism

The invention discloses an ultrasonic detection method for the seal weld of a nuclear reactor control rod driving mechanism. The ultrasonic detection method comprises the following steps: S1, selecting an ultrasonic apparatus and a surface wave probe to serve as detecting equipment, and making a reference test block and a compensation quantity test block according to the physical performance of aworkpiece to be detected, wherein the reference test block is provided with notches of different burial depths; S2, performing ultrasonic detection on the notches of different burial depths in the reference test block, and drawing a depth amplitude curve of the back defect depth of a thin plate; S3, performing ultrasonic detection on the compensation test block to obtain a depth amplitude curve ofthe seal weld; S4, finishing the detection data collection of the workpiece to be detected, and calculating the defective burial depth of the weld by using the depth amplitude curve of the seal weldin order to evaluate the we