This clinical study aims to evaluate whether short-term personalized nutritional support, when combined with structured health education, can improve nutritional status, quality of life, and clinical outcomes in patients who have undergone surgery for colorectal cancer (CRC). Colorectal cancer is one of the most common cancers worldwide, and many patients experience malnutrition and poor physical condition during treatment, which can negatively affect recovery and long-term survival. In this multicenter, randomized, controlled clinical trial, approximately 360 postoperative CRC patients will be enrolled and randomly assigned to one of four groups: (A) nutritional enhancement combined with health education, (B) health education alone, (C) nutritional enhancement alone, or (D) standard care (control group). Nutritional support will include individualized diet counseling and oral nutritional supplements tailored to each patient's needs. Health education will be delivered using an Internet Plus approach, including weekly educational videos and expert consultations focusing on nutrition, physical activity, and mental health. The primary objectives are to determine whether these interventions can improve patients' short-term nutritional status and quality of life. Secondary outcomes include the impact of interventions on long-term survival, treatment-related side effects, patient adherence to nutrition recommendations, and psychological well-being. This study will also investigate the biological mechanisms underlying the clinical effects by analyzing changes in the gut microbiome, blood-based metabolic profiles, and immune responses. Blood, stool, and tumor tissue samples will be collected and analyzed using advanced techniques, including untargeted metabolomics, metagenomics, and single-cell sequencing. This trial is designed to provide evidence for the integration of nutritional strategies into routine cancer care, and to guide the development of more personalized, effective nutrition-based therapies for colorectal cancer patients. Participants will be followed for up to annually up to 5 years to evaluate both clinical outcomes and biological markers of response.