CSK-IB test block is improved on the basis of IIW test block. The main uses are :1 Using R100mm curved surface to measure the incident point and front length of inclined probe; 2 The Angle of refraction of the inclined probe is measured with 50 and 1.5mm round holes; 3 The deviation of the beam axis of the inclined probe was measured by using the right Angle edge of the test block. 4. Horizontal linearity, vertical linearity and dynamic range of 25mm thickness flaw detector; 5 Use 25mm thickness to adjust the longitudinal wave detection range and scanning speed; Use R50 and R100mm surfaces to adjust the S-wave detection range and scanning speed; 7 The resolution of the inclined probe was measured with three step holes of 50, 44 and 40mm.