Chinese-node telescope of Stellar Observations Network Group (SONG) has a primary

mirror 1m in diameter with flat back, which will be supported actively. The performance

evaluation of the telescope’s active optics system is conducted. Finite element analysis (FEA) is employed to analyze the optical surface figures of the primary mirror, and two optimizations are carried out by using ANSYS: (1) the locations and forces of axial supports are optimized with the telescope pointing to zenith; (2) the lateral support forces are calculated with the telescope pointing to horizon. Axial support force sensitivities are calculated in a case that a single axial support has a force error of 0.5N. The correction ability of the active support system is analyzed when an arbitrary axial support is failure. Several low order Zernike modes are modeled with MATLAB procedure, and active optics corrections are applied to these modes. Thermal deformation of the mirror is also corrected using active support system.