The invention belongs to the medicine field, and specifically relates to an intra-intestinal nutrient emulsion for tumor patients. The emulsion is characterized by comprises the following effective components: protein, fat, carbohydrate, total dietary fiber, green tea theine, taurine, L-carnitine, composite vitamins and mineral substances, and water. The protein is provided in an amino acid powder form, the formula of the amino acid powder is adjusted on the basis of 20 kinds of protein amino acids, wherein methionine is replaced by homocysteine, glutamine and glutamic acid are not added, the tryptophan content is low, and the content of branched chain amino acid reaches 35% or more; fat is provided in a saturated aliphatic acid or unsaturated fatty acid form, wherein in the unsaturated aliphatic acid the value of omega-6 / omega-3 is equal to 2-6 / 1; and the carbohydrate is provided in a form of glycerin, glucose, fructo-oligosaccharide or lentinan. Besides one prominent characteristic of the emulsion is that the emulsion is a high-fat and low-sugar type, and the ratio of sugar to fat is 1:1. The emulsion formula is adjusted according to the nutrient and metabolism requirements of tumor patients so as to develop an individualized intra-intestinal nutrient preparation for tumor patients, the preparation can provide balanced nutrients for tumor patients, effectively cures the malnutrition symptom, improves the life quality of patients, and can also be used to assist the tumor treatment.