高空太阳能无人机（UAV）在起飞爬升阶段飞行速度慢，爬升率低，爬升时间很长，需要螺旋桨提供大拉力以实现快速爬升，但低空空气密度大，螺旋桨处于小转速、大扭矩状态。在20 km高空飞行阶段，空气密度只有地面的1/14，要求螺旋桨处于高转速、高效率状态。受动力系统的功率限制，定桨距螺旋桨无法匹配这2种状态，需要采用变桨距技术，实现低空的小桨距、低转速、大拉力构型，高空的大桨距、高转速、高效率构型。提出了一种满足多设计点螺旋桨气动外形优化方法和多工况变桨距角策略。建立了基于片条理论的螺旋桨多设计点气动外形优化模型，实现了螺旋桨各剖面弦长和扭转角分布等外形参数优化；在此模型上加入了考虑桨距角变化的快速气动计算模型，实现了多工况下变桨距角策略。通过对比定桨距和变桨距下的螺旋桨气动性能，结果表明，基于螺旋桨多设计点气动外形优化模型设计的螺旋桨在高空多设计点效率均在80%以上，有利于太阳能无人机的长时间飞行；考虑变桨距优化策略的螺旋桨，在起飞爬升工况拉力最高提升78.42%，可以提供更大的爬升率，有利于太阳能无人机在起飞时快速通过对流层到达高空设计点飞行。

The high-altitude solar powered Unmanned Aerial Vehicle（UAV） has a slow flight speed， low climb rate and long climb time in the take-off and climb stage， the propeller needs to provide large pull force to achieve fast climb. However， the low-altitude air density is high， and the propeller is in the state of low speed and high torque. At the altitude of 20 km， the air density is only 1/14 of the ground， requiring the propeller to be in a state of high speed and high efficiency. Due to the power limitation of the power system， fixed-pitch propellers cannot match these two states， so variable pitch technology is needed to realize the configuration of small pitch， low speed and large tension at low altitude， and large pitch， high speed and high efficiency at high altitude. This paper presents a method of aerodynamic profile optimization for propeller with multiple design points and a strategy of variable pitch angle under multiple operating conditions. The aerodynamic profile optimization model of propeller with multiple design points was established based on standard strip analysis， and the profile parameters of propeller were optimized， such as chord length and torsion angle distribution. A fast aerodynamic calculation model considering pitch angle variation is added to the model to realize the strategy of variable pitch angle under multiple working conditions. By comparing the aerodynamic performance of the propeller under fixed pitch and variable pitch， the results show that the efficiency of the propeller designed based on the aerodynamic shape optimization model of the propeller at multiple design points at high altitude is more than 80%， which is conducive to the long-term flight of the solar powered UAV. Considering the propeller with variable pitch optimization strategy， the maximum pulling force can be increased by 78.42% in take-off climbing condition， which can provide a larger climbing rate， which is conducive to the solar powered UAV quickly flying through the troposphere to reach the upper design point during take-off.