Background: Valvular heart disease is a leading cause of death worldwide, with aortic valve disease having the highest mortality rate. Currently, prosthetic aortic valve replacement is a significant treatment option for the majority of patients. However, the efficacy of prosthetic valves is highly dependent on the geometry of the aortic root. With the development of precision medicine and computational fluid dynamics, patient-specific modeling and simulation of prosthetic heart valves increasingly become the forefront of current research. Methods: In this study, we propose an approach for designing patient-specific prosthetic aortic valves using fluid-structure interaction (FSI) analysis. Firstly, the aortic root model was reconstructed from the Computed Tomography (CT) images. We then implemented a parametric valve design. The leaflets were directly attached to the aortic root, determined by the attachment curve, the free edge, and the belly curve. We selected seven key points, including the point of leaflets coaptation, three points located at the ends of the free edge, and three points located at the bottom of the attachment curve. This allowed for designing various leaflet geometries for the patient-specific aortic root. Furthermore, each valve model was simulated using FSI method. We evaluated velocity, effective orifice area (EOA) and coaptation area (CA) to study its performance. Results: The results showed that the valve gradually opened (0.0-0.20 s) at the start of systole, remaining fully open (0.20-0.25 s) for sufficient blood flow. Subsequently, the valve promptly closed to prevent regurgitation. The patient-specific valve demonstrated a large EOA (3.82-4.10 cm2) and a proper CA (3.41-4.43 cm2), indicating satisfactory performance. Conclusion: Our study investigated an approach for designing patient-specific prosthetic aortic valves and evaluated hemodynamic parameters using FSI simulations. This provides promising insights into the design of prosthetic aortic valves and potentially serves as a valuable tool to assist patient-specific aortic valve replacement.