Ducted propeller flight platforms often encounter complex and variable operating conditions during mission execution. Traditional ducted fixed-pitch propellers struggle to fully adapt to multiple design point conditions, resulting in degraded aerodynamic performance. To simultaneously meet the high thrust requirements in hover conditions and the high efficiency demands in forward flight, variable-pitch technology becomes essential for maintaining superior aerodynamic efficiency across multiple design points. This study establishes a multi-design-point aerodynamic optimization method for ducted variable-pitch propellers. Leveraging airfoil lift-drag surrogate models, rapid aerodynamic calculation models were developed: a blade element theory-based propeller performance model and a ducted propeller analysis model using panel method. Through parametric optimization of blade chord length, twist angle, and improved Hicks-Henne function-based duct profile parameterization, a mathematical optimization model was constructed using panel method. This framework was applied to optimize a 3.6-meter diameter ducted propeller. Results demonstrate that the optimized variable-pitch configuration achieves 16.74% total thrust enhancement at 0 m/s wind speed and 2.03% aerodynamic efficiency improvement at 10 m/s wind speed compared with fixed-pitch counterparts, validating the effectiveness of the proposed multi-design-point optimization methodology.