Abstract: In order to provide an optimization scheme for the parameter design of the discharge head of CO₂ fracturing device, ANSYS-CFX was used for numerical simulation and emulation of the flow field inside the discharge head of CO₂ fracturing device, the maximum pressure of the single-hole discharge head of CO₂ fracturing device under different inlet gas pressure, divergence cone and diameter of contraction section was analyzed, while an orthogonal test table composed of 25 numerical models was established. The experimental analysis shows that when the inlet pressure is 290 MPa, the divergence cone is 40 cm, and the diameter of contraction section is 0.073 m, the discharge head of CO₂ fracturing device comes to the maximum pressure, reaching 317.2 MPa. The results provide theoretical support for improving the safety of CO₂ fracturing device.