介绍了合肥８００ＭｅＶ储存环ＦＥＬ光学速调管改造成同步辐射波荡器的设计与计算过程，给出了改造方法，计算了波荡器的光通量与亮度并给出了光通量与亮度曲线．计算结果表明，改造后的波荡器可以将目前辐射亮度提高两个多数量级，使许多目前光源亮度下无法开展的研究工作得以进行． This paper introduces the design and calculation process of the FEL optical klystron in the storage ring of Hefei 800MeV into a synchrotron radiation undulator. The reconstruction method is given, the luminous flux and brightness of the undulator are calculated, and the luminous flux and brightness curve are given. The calculation results show that the modified undulator can increase the current radiation brightness by more than two orders of magnitude, which makes the research work that can not be carried out under the current brightness of light source.