The invention discloses a method for preparing medicine albumin nanoparticles, and belongs to the technical field of medicine preparations. According to the method disclosed by the invention, metal salt without biologic toxicity or a non-salt compound is used as a coagulator, a natural compound without biologic toxicity is used as a cross-linking agent, and a few of solvents which are nearly nontoxic, such as ethanol, are used as a medicine solvent. Nanoparticles are formed through energy instantaneously released through cavitation. The preparation method of the medicine albumin nanoparticles disclosed by the invention has the advantages that the preparation method is environmentally-friendly, organic solvents having medium and high toxins are not used, an emulsifying and volatilizing process is not included, besides, the solidification effect and the dispersion effects of the nanoparticles are completed at the same time, a few technology steps are used, and the time consumption is short. The particle diameter of the medicine albumin nanoparticles prepared by the method is generally smaller than 800nm.