Nutritional status of hematologic malignancy patients is crucial for enhancing treatment efficacy and quality of life. By reviewing domestic and international guidelines and literature on oral nutritional supplementation (ONS) for hematologic malignancy patients, this study summarizes such key aspects of ONS therapy as pre-use nutrition screening and assessment, timing of ONS initiation, product selection, nutrient ratios, and nursing care, in an effort to provide a reference for managing oral nutritional supplementation in this patient population.