Abstract: With the space technologies progress rapidly, demand of large-size mirrors is intensively growing. In this paper, the developing trend of large-size space mirrors was discussed from the angles of material and fabrication technology. Taking 1.0 m aperture technical validation brazed mirror as an example, the design and fabrication of segments, joining and optic machining were analyzed. In addition, the 1.0 m aperture technical validation brazed mirror was performed environmental tests including thermal-vacuum test, vibration test and anti-radiation test in order to evaluate its engineering applicability. The experimental results show that the surface figure of the 1.0 m aperture technical validation brazed mirror changed from 0.038λ (λ=632.8 nm) to 0.037λ and 0.036λ after thermo-vacuum test and vibration test. Additionally, reflectivity of the brazed mirror basically kept stable after ⁶⁰Co γ-ray radiation test, indicating a brilliant application prospect.