针对大口径光电经纬仪主镜的支撑结构对主镜面形精度的影响，对大口径光电经纬仪的Φ1 000 mm主镜的支撑结构进行了研究。分析了现有轴向和径向支撑结构的局限性，提出了适用于大口径主镜的新的轴向和径向支撑结构，并阐述了该支撑结构的工作原理和优势。利用有限元分析软件建立了主镜的参数化模型，优化了主镜轴向支撑点和径向支撑点的位置，并分析了主镜光轴在竖直和水平位置两个极限状态下的面形误差，计算得到了主镜在竖直状态下面形误差RMS值为2.52 nm；在水平状态下面形误差RMS值为4.33 nm。对主镜进行装调后，用光学干涉仪检测得到主镜光轴水平时面形精度RMS值为19.87 nm。仿真分析结果和实物检测结果都满足设计指标中面形误差RMS值小于λ/30的要求(λ=632.8 nm)，验证了轴向和径向支撑结构的可行性。

In consideration of the effect of support structure for the primary mirror of a large aperture theodolite on the surface figure precision of the primary mirror, the support structure of a Φ1 000 mm primary mirror was explored. The disadvantages of existing axial and radial supporting structures were analyzed and a new axial and radial complex supporting structure for large aperture primary mirror was presented. Then, the performing principle and the advantages of the supporting structure were discussed. A parameter model of primary mirror was built based on the finite element analysis software, the axial and the radial supporting positions were optimized and the surface figure errors of the optical axis for the mirror in vertical and in level orientations were analyzed. Obtained results show that the surface figure precisions are 2.52 nm and 4.33 nm in RMS values as the mirror's optical axis in vertical and level orientations, respectively. After alignment, the primary mirror is tested in its optical axis is in level orientation by an optical interferometer, and the mirror's RMS value is 19.87 nm in the measurement. The results fully satisfy the precision requirement of RMS value less than λ/30 (λ=632.8nm), which proves the feasibility of the axial and radial supporting structure mentioned above.