This study aimed to establish the optimal conditions for producing gluten-free noodles by varying the amount of pregelatinized rice flour added to the regular rice flour and investigating their quality characteristics. With an increase in the amount of added pregelatinized rice flour, the brightness of the noodles decreased, and the color became more yellow both before and after cooking. Adding pregelatinized rice flour to the noodles also increased hardness, elasticity, chewiness, stickiness, and adhesiveness. The textures of the two groups of samples (PR-10 and PR-15) were similar to that of the control, indicating comparable structural characteristics. Furthermore, the absence of gluten made it inherently challenging to form gluten-free noodles. Still, adding pregelatinized rice flour improved the processability of the dough, leading to better noodle formation. An optimal addition of 15% pregelatinized rice flour was deemed suitable for optimal noodle formation in gluten-free noodles. This study established blending conditions using pregelatinized rice flour to improve the poor processability of gluten-free noodles. The findings are expected to be valuable for the industry’s future development of gluten-free processed food.