The invention relates to a quantitative method for quickly recognizing influences of human activities on lake water bloom in the field of environment and management. The quantitative method is generally suitable for the management and decision-making aspect of the lake water bloom problem and especially suitable for quickly recognizing and quantifying the influences of human activities on the lake water bloom. The quantitative method for quickly recognizing the influences of human activities on the lake water bloom is proposed for the defects that at present, human activities have the serious influences on lakes especially lakes located in cities or suburbs, quantitative methods for the lake water bloom mostly place extra emphasis on the researches of formation mechanisms and evaluation and prediction models of the water bloom, parameters included in the models are many, forms are complex, and the influences of human activities on the water bloom are less referred. According to the method, the lake water bloom degrees are quantified based on a multiple linear regression method, and the influence degrees of human activities on the lake water bloom are quantified through background value comparison. Results can be used for providing the definite governing direction for administrators and decision makers, and the administrators and decision makers are inspired to prevent and govern the lake water bloom from the angle of human activities.