Background and Aims The pathogenesis and development of aortic dissection are not fully understood at present. However, a lot of studies have shown that hemodynamic factors have an important influence on the occurrence and development of aortic dissection. This study was conducted to determine the changing pattern of the hemodynamic parameters in the aorta without dissection and with dissection of different development stages by computational fluid dynamics method, aiming to investigate the occurrence and development of dissection from the perspective of fluid dynamics.Methods Based on the aorta size data of a patient with type B aortic dissection, the idealized aortic models without dissection and with dissection in different development stages were constructed using 3D modeling software Pro/E. Two-way fluid-structure coupling simulation was completed by Workbench platform, and the changing pattern of the hemodynamic parameters such as blood velocity, pressure and Von Mise stress of vascular wall were analyzed.Results During the accelerated ejection period, the maximum blood velocity increased about 0.6 m/s with the presence of the dissection, and the blood flow condition in the false lumen became more complex with the development of the aortic dissection. The maximum blood pressure increased about 0.3-0.6 kPa, and the hypertensive area of the lateral wall of the ascending aorta entrance was also enlarged. The peak and fluctuation of the maximum Von Mise stress in the vascular wall were increased with the development of the aortic dissection, and the maximum Von Mise stress was mainly located in the laceration of the tear location, the lateral wall and the outer wall of the false lumen.Conclusion In the presence of aortic dissection, the false lumen compresses the true lumen, resulting in increased blood velocity of vascular branches and increased blood pressure and hypertension area of the ascending aorta. Vortex near the tear location may cause further tearing or even rupture the blood vessel. The risk of further tearing and rupture of the blood vessel increases with the development of the aortic dissection, and the prevention of rupture of the blood vessel at the tear location, lateral wall and the outer wall of the false lumen should be focused.