A greening comprehensive utilization technology of flos sophorea immaturus is implemented by the following steps: a solvent is used to extract under a pressure reduction condition, so as to extract effective components, namely flos sophorea immaturus pigment, rutin, flos sophorea immaturus polysaccharides and flos sophorea immaturus protein (water-soluble substance) in the flos sophorea immaturus by one step, then the extracted components are separated one by one, and extracted flos sophorea immaturus residues contain water-insoluble protein, and can be used as high protein feed after being processed. According to the technology, flos sophorea immaturus resources are comprehensively utilized, the pollution of acid water generated in the rutin extraction process to the environment in the prior art is avoided, and the defect that by other methods, only the simple component, namely the rutin can be extracted, while other components are wasted, so that a great amount of resources are wasted can be remedied; the greening comprehensive utilization of the flos sophorea immaturus resources is characterized in that the social and economic sustainable development is realized, no harmful effect can be generated in the working process, moreover, the flos sophorea immaturus resources can be fully utilized to the maximum extent; raw materials are fully transformed into a product, so that the pollution can not be produced as soon as possible; synchronous extraction and comprehensive utilization of all component can be realized, so that the economic value of the flos sophorea immaturus is effectively improved.