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。为满足透镜面形精度RMS 值优于1~2 nm 的指标要求，本文提出了一种具有整体径向挠性的透镜多点均匀支撑结构，基于自重变形和热变形对支撑块尺寸进行了优化设计，分析了透镜在优化后的支撑结构下由自重和热载荷引入的面形变化情况，结果表明：自重引起的透镜上表面面形去除power 项后RMS 为0.429 nm，下表面面形去除power 项后RMS 为0.294 nm；热载荷引起的透镜上表面面形RMS 为0.409 nm，下表面面形RMS 为0.063 nm，能够满足光刻投影物镜中透镜的高精度面形要求。

The lens surface figure precision of lithography objective lens is a key factor which influences the system imaging quality. In order to meet lens surface figure accuracy RMS better than 1~2 nm, this article introduces a lens support structure with multi point equal supporting which wholly has the radical freedom. Then, based on gravity deformation and thermal deformation, the structure optimization is finished. Finally, due to gravity and thermal load, the finite element analysis of lens deformation is done. Results are as follows: lens surface figure RMS of the upper surface causing by gravity is 0.429 nm, while the lower surface is 0.294 nm, and lens surface figure RMS of the upper surface causing by thermal load is 0.409 nm, while the lower surface is 0.063 nm. The results indicate that the lens supporting structure is of high precision, and can be satisfied with the lithography objective lens surface accuracy.