Objective: To investigate the correlation between quantitative immunochemical fecal occult blood test(qFIT)values and the severity of different types of colorectal mucosal lesions.Methods:A retrospective analysis was conducted on the clinical data of 80 patients who underwent qFIT and colonoscopy examinations concurrently at Jingdezhen First People"s Hospital from January 2021 to January 2025. Patients were categorized based on colonoscopy and pathological findings into the normal group (n=30), colitis group (n=10), non-adenomatous polyp group (n=15), adenomatous polyp group (n=15), and colorectal cancer group (n=10). Differences in qFIT values were compared across groups. Spearman"s rank correlation analysis assessed the relationship between qFIT values and the severity of colorectal mucosal lesions. Results: qFIT detection values exhibited a stepwise increase with increasing severity of colorectal mucosal lesions (P<0.001). Spearman correlation analysis confirmed this positive correlation (P<0.001). Logistic regression analysis demonstrated that qFIT values are an independent predictor of high-risk lesions (P<0.001). Conclusions: qFIT test values correlate closely with the severity of colorectal mucosal lesions, demonstrating high clinical utility for screening colorectal cancer and high-risk lesions such as adenomatous polyps. It serves as a significant non-invasive indicator for risk stratification.