The preparation quality of Ni-based single crystal alloy (NSCA) with gas film pore structure has become a key factor restricting the application and development of high-performance aero-engine equipment. However, due to the difficulty of quantitatively expressing the microstructure changes during the preparation process, it is difficult to quantitatively evaluate the preparation quality under different processes. In the present study, taking the advantages of ultrasonic guided wave that is sensitive to metal material micro-damage and has high detection efficiency and detection accuracy, excitation frequency (2.05 MHz) and benchmark characteristic parameters (7.58 e^-4/mm) of NSCA are determined, and then the influence mechanism of different preparation quality defects on the nonlinear parameters of guided wave is clarified by theoretical and experimental analysis, which will provide theoretical basis research for the subsequent efficient and controllable preparation of NSCA with gas film pore structure.