光刻投影物镜中透镜的面形精度是影响光学系统成像质量的关键因素之一。为实现透镜面形精度均方根（RMS）值优于2 nm的高精度指标，提出一种轴向多点挠性支撑、径向三点可调式定位的光学透镜支撑结构。基于自重变形对支撑结构进行优化设计，深入分析在此支撑结构下自重和热载荷对透镜面形影响。结果表明，重力引起的透镜上表面面形RMS值为0.186 nm，下表面面形RMS值为0.15 nm。热载荷引起的上表面面形RMS值为0.55 nm，下表面面形RMS值为0.54 nm。采用这种透镜的支撑结构，能够满足光刻投影物镜中透镜的高精度面形要求。

The surface-profile precision of objective lens for lithography is a key factor which influences the imaging quality. In order to achieve the root-mean-square (RMS) value of lens surface-profile accuracy which is better than 2 nm, a novel lens support structure with multi-points axial flexible support and three-point length-changeable radial holding is proposed, and then structure optimization by the influence of gravity deformation compensation is realized. Finally, the finite element analysis of lens deformation due to gravity and thermal load is done. The results are as follows: for the deformation of lens surface caused by gravity, profile RMS of the upper surface is 0.186 nm, while RMS of the lower surface is 0.15 nm; for the deformation of lens surface caused by thermal load, profile RMS of the upper surface is 0.55 nm, while RMS of the lower surface is 0.54 nm. The results indicate that the lens supporting structure can meet high-precision requirements of surface profile of the objective lens for lithography.