Abstract: The optical fiber image inverters are the key components which applied in low-light level night vision device, and the optical fiber image inverters with large aperture can achieve the detection of wide field of view, large view and further visual range. However, the existing twisting operation process cannot produce the qualified products. The twisting operation process with rotation differential velocity combined with double internal furnace heating design was adopted, and finally the large-aperture optical fiber image inverters with required performance indexes were prepared. The test results show that the angle concentration amount in twisting region is decreased to 5.98 °/mm, which significantly improves the edge resolution of the large-aperture optical fiber image inverters.