This study investigated the physicochemical and digestive properties of glycated tilapia scale collagen peptides (G-TSCP) reacted with galactooligosaccharides (GOS) under different thermal processing conditions (80, 100, 120 ℃). The glycation degree was evaluated through analysis of colorimetric parameters (ΔE), pH variation, fluorescence intensity, grafting degree, and furosine level. Structural characterization was performed using Fourier transform infrared spectroscopy (FTIR), while digestibility was assessed through in vitro simulated gastrointestinal digestion coupled with size exclusion chromatography (SEC). Thermal processing analysis revealed significant time-dependent alterations (P<0.05): grafting degree (9.58%±0.23%), ΔE values (4.39±0.13), and fluorescence intensity (502803±8089 Rfu) reached maximum levels at 100 ℃/60 min treatment, while the most pronounced pH reduction (7.55±0.03) occurred at 120 ℃/20 min processing. Significantly positive correlations were observed between grafting degree and ΔE (r=0.83, P<0.01) and fluorescence intensity (r=0.77, P<0.05), while pH was negatively correlated with these parameters (r=−0.81, P<0.01; r=−0.87, P<0.01). Secondary structure analysis indicated that glycation-induced conformational changes were characterized by the decrease of β-turn content (from 46.5% to 24.6%) and the increase of random coil structures (from 12.4% to 33.6%) under the processing condition of 120 ℃/20 min when compared to native TSCP. Digestibility assessments demonstrated that G-TSCP exhibited lower hydrolysis degree (from 22.18% to 68.8%) when compared to native TSCP (P<0.05), with the 120 ℃/20 min processed sample showing minimal intestinal digestibility (6.65%±0.18%). SEC analysis revealed that thermal processing at both 100 ℃ and 120 ℃ significantly enhanced the ratio of 1000~5000 Da fractions in G-TSCP, showing higher proportions than unmodified TSCP. Under optimal heating conditions (100 ℃/40 min), the glycated tilapia scale collagen peptide (G-TSCP) exhibited a grafting degree of 8.07% and a furosine content of 5.83 μg/100 mg TSCP, indicating moderate glycation. Compared to native TSCP, G-TSCP demonstrated significantly reduced gastrointestinal hydrolysis (10.27%) (P<0.05), suggesting enhanced digestibility resistance. These findings reveal that controlled thermal glycation can modulate collagen peptide structure and attenuate digestion, providing a potential strategy for designing sustained-release bioactive peptide formulations.