本研究針對大口徑反射鏡系統進行設計以及最佳化,包含主鏡背部減重設計以及其背向撓性支撐機構最佳化。最佳化設計流程使用了電腦輔助設計軟體進行模型建置,隨後匯入到有限元素軟體執行靜態分析,接著透過光機轉換程式將有限元素分析後結果轉換為光學性質,最後則是將有限元素及光機轉換分析結果傳輸至最佳化求解器中,最佳化演算法使用梯度法進行一系列優化工作。主鏡減重最佳化中反射鏡使用了背向曲面設計,除了提高減重比之外亦保持良好的機械與光學性質;另一方面,採用背向組裝的撓性機構設計,考慮在一倍重力加速度下以及環境溫度提升4度時分析,目的為使整體系統光學性質達到最佳。由最終最佳化結果顯示主鏡使用新設計成功得到減重比約為83%設計,撓性機構最佳化則是在溫度以及重力作用下光學性質有改善,如主鏡系統峰谷值(Peak to Valley, PV) 從30.79 nm改善為19.75 nm。;The mirror structure and support system of remote sensing instrument (RSI) were designed in optimization process. This study contained lightweight design of mirror and its flexure mount. The design has utilized computer-aided software as model building method. Then the model was imported to finite element software for static analyzing. Next, the FEM node data was transferred into several optical characteristic values through opto-mechanical program. Finally, the analysis results were transferred back to the optimization solver. A new lightweight type of mirror was proposed in our laboratory. The purpose of this study is to enhance the mass reduction ratio while maintaining both optical quality and mechanical rigidity. In addition, the multiple environments were considered to design the flexure mount. According to the final optimization result, the study successfully found a mirror which mass reduction ratio is about 83%, its performance also has good improvement with combing flexure under gravity loading and thermal changed, the PV value improved from 30.79 nm to 19.75 nm.