In this study, the main factors affecting the signal-to-noise ratio (SNR) of a super-second-generation image intensifier are investigated through theoretical analysis combined with experimental validation. The results show that photocathode sensitivity, brightness gain, the opening area ratio of the Microchannel Plate (MCP), the secondary electron emission coefficient at the first electron collision, and the MCP tilt angle all influence the SNR. The SNR increases with higher photocathode sensitivity—rising by 49.6% when the sensitivity increases from 356 μA/lm to 1013 μA/lm. Conversely, the SNR decreases with the increase of luminance gain—dropping by 12.3% as luminance gain increases from 5000 cd·m^-2·lx^-1 to 20000 cd·m^-2·lx^-1. The SNR is negatively correlated with the MCP noise factor. A lower noise factor is associated with a larger MCP opening area ratio and a higher secondary electron emission coefficient during the first electron collision. Additionally, the MCP noise factor first decreases and then increases with increasing MCP tilt angle. Based on these findings, the optimal values for the MCP opening area ratio, the secondary electron emission coefficient at first collision, and the tilt angle were determined within a defined range of sensitivity and brightness gain. Under these optimized conditions, the MCP noise factor is reduced by 38.0%, and the SNR is improved by 26.9% compared to the standard configuration of the super-second-generation image intensifier. This work lays a strong foundation for further enhancing the SNR performance of super-second-generation image intensifiers.