The incorporation of polysaccharides can effectively lower the glycemic index (GI) of rice noodles but may also negatively impact their cooking and eating quality. This study explores the use of solid-state fermentation with Limosilactobacillus fermentum and the addition of lysine to enhance the cooking and eating quality of high-fiber rice noodles (HFRN). Optimal fermentation conditions—10% Limosilactobacillus fermentum inoculum, 30 °C fermentation temperature, and 72-h fermentation time—along with a 3% lysine addition, were identified. The results revealed a significant increase in cooking quality and sensory characteristics of the rice noodles under these conditions. Compared to the control, the treated rice noodles exhibited higher sensory scores (increased by 17%), lower broken strip rates (reduced by 77.99%), and superior textural properties. Further analysis using Fourier Transform Infrared Spectroscopy (FTIR), rapid viscometer analyzer (RVA), and differential scanning calorimetry (DSC) demonstrated that fermentation and lysine addition inhibited starch granule swelling, leading to decreased pasting properties (viscosity drop of 22.77–29.94% in all stages). Additionally, the retrogradation rates were reduced, and thermal stability was markedly increased (ΔH increased by 190.90%). These findings suggest that solid-state fermentation combined with lysine supplementation offers a promising strategy for enhancing the cooking and eating quality of HFRN.