The invention discloses an assessment method of hydrogen damage to a water wall tube of a boiler. The method comprises the steps as follows: 1), a sampling tube in the water wall tube of the boiler is assessed; 2), a test object is selected; 3), a supersonic detector is equipped, 4), the test object is subjected to supersonic detection; 5), according to the step 4), a product logarithmic function and a sonic path distance graph are established; 6); a supersonic attenuation coefficient a0 of the test object is obtained; 7), supersonic detection of the sampling tube is performed; 8), according to the step 7), a product logarithmic function and a sonic path distance graph are established; 9), a supersonic attenuation coefficient a1 of the sampling tube is obtained; 10), a hydrogen damage degree factor value delta of the water wall tube of the boiler is obtained; and 11), an assessment conclusion of the hydrogen damage to the water wall tube of the boiler is drawn. According to the method, special processing of the tested material is not required, the process is simple, the operation is convenient and rapid, the conclusion is accurate, the requirement for the detection environment is less strict, and the efficiency is substantially improved.