为了预估碳化硅反射镜在空间零重力环境下的面形精度，本文开展了在地面环境下利用方位反向技术提取碳化硅反射镜零重力面形的研究。首先，介绍了方位反向技术提取零重力面形的理论依据; 其次，利用有限元分析软件，分析了方位反向对反射镜面形的影响; 然后，按照试验流程，先后检测了反射镜在0°和180°状态的面形精度，计算两次检测数据的平均值，得到了反射镜零重力面形。结果表明: 反射镜地面零重力面形误差RMS值为123 nm，能够满足设计指标要求。最后，对数据可信度进行了分析，确认了试验数据真实可信。该结果预示了反射镜在空间零重力环境下的面形精度，对反射镜光学加工与装调有重要的指导意义。

In order to estimate the SiC mirror surface figure under the space zero-gravity environment, extracting zero-gravity surface figure of SiC mirror by orientation reversal under ground environment was studied. Firstly, the principle of extracting zero-gravity surface figure by orientation reversal is introduced. Secondly, the effect of orientation reversal on mirror surface figure is analysed by finite element analysis software. Then, according to the flow chart, mirror surface figure of 0° and 180° conditions are tested successively, and the zero-gravity surface figure is obtained by average two measurements. The data indicate that the RMS value of the ground zero-gravity surface figure of mirror is 123 nm, which meets the design requirement. Last, data credibility is analysed and confirmed. The obtained results indicate the mirror surface figure in the zero-gravity environment of space, which has important significance for optical fabrication and alignment of mirror.