Due to their excellent high-temperature performance and lightweight properties, SiC/SiC composites are widely used in high-temperature components of aerospace engines. However, defects like porosity and delamination can occur during their fabrication, affecting material performance and necessitating efficient non-destructive testing methods. Extensive research indicates that CT inspection is one of the most effective methods for detecting defects in SiC/SiC composites. Traditional CT scanning often requires several hours, leading to high time consumption and costs. In contrast, the fast scan mode continuously exposes the sample during rotation, significantly reducing scanning time. While fast scanning may introduce issues like image trailing and noise, this study compares image resolution, noise distribution, and defect detection capabilities across different scanning modes. It proposes methods to optimize scanning parameters, aiming to enhance detection efficiency without compromising image quality. Experimental results indicate that fast scan technology can substantially increase scanning speed without significant loss in spatial resolution. Although image noise increases as the number of projections decreases, adjusting parameters such as current can effectively mitigate noise effects. The study concludes by proposing strategies to balance image resolution, noise, and scanning time, providing technical support for fast scan of industrial CT testing for SiC/SiC composites.