For the detection of defects in austenitic stainless steel,a comparative analysis of water im-mersion C-scanning experiments is carried out on test pieces with pre-buried defects using two methods.The experimental results verified the effectiveness of the full-focus C-scanning methods of line and annular array:The detection time of the line array linescan is 1min12s,which is much lower than the ring array full-focus detection detection of 21min;the full-focus method possesses stronger defect contour reduction capa-bility;the annular array possesses stronger detection capability of defects with large depth.