The invention relates to a method for comprehensively extracting effective ingredients in tea. The method comprises the following steps of: with a faintly acidic water solution as a main extraction solvent and a certain amount of organic solvent as an auxiliary extraction solvent, carrying out step-by-step extraction on water extracts to obtain four effective ingredients, namely tea polyphenol, caffeine, tea polysaccharide and theanine; and meanwhile, extracting tea protein from tea residues by using an alkali dissolution and acid deposition method. According to the method, as water is used as the main solvent, the cost is low, the reactions are mild and active ingredients are favorably preserved; as a certain amount of organic solvent is used as the auxiliary extraction solvent, the problems of overhigh cost and product pollution caused by use of a large amount of organic solvents are solved; meanwhile, five effective ingredients, namely the tea polyphenol, the tea polysaccharide, the caffeine, the theanine and the tea protein are extracted, and therefore high extraction rate, high purity and high utilization rate of tea are achieved; the solvents are recycled in the extraction process, so that the preparation cost is reduced; and no alkali and acid waste liquor is discharged in the overall process, and therefore the method is environment-friendly. The overall preparation flow is high in efficiency and low in cost, and therefore the method has a favorable application value.