A method for preparing a protein particle with a poorly water-soluble drug encapsulated therein, comprising the following steps: i) dissolving a poorly water-soluble drug and a liquid solubilizer into a good solvent; ii) partially or fully removing said good solvent from the product of step i) to obtain a liquid product; iii) mixing the product of step ii) with a powder-form protein; iv) dispersing the product of step iii) in a poor solvent; wherein said protein is albumin; wherein said poorly water-soluble drug comprises one or more selected from the group consisting of paclitaxel, docetaxel, camptothecin, hydroxycamptothecin, rapamycin, doxorubicin, itraconazole and nimodipine; wherein said liquid solubilizer is selected from the group consisting of liquid polyethylene glycol, polysorbate wherein said good solvent is defined as follows: 1g (ml) of poorly water-soluble drug is capable of being dissolved in less than 30 ml of good solvent for the poorly water-soluble drug; wherein said poor solvent for the poorly water-soluble drug is an aqueous medium; in step i), the mass ratio of poorly water-soluble drug to the protein in step iii) is 1:0.1~15; in step i), the mass/volume ratio of poorly water-soluble drug to liquid solubilizer is 0.1g:0.01~10ml; in step iii), the mass/volume ratio of the poorly water-soluble drug to the poor solvent is 0.1g:1~100ml; wherein said poor solvent has a pH of 5∼8; wherein the method for preparing the protein particle is performed at a temperature of less than or equal to 45°C. i) dissolving a poorly water-soluble drug and a liquid solubilizer into a good solvent; ii) partially or fully removing said good solvent from the product of step i) to obtain a liquid product; iii) mixing the product of step ii) with a powder-form protein; iv) dispersing the product of step iii) in a poor solvent; wherein said protein is albumin; wherein said poorly water-soluble drug comprises one or more selected from the group consisting of paclitaxel, docetaxel, camptothecin, hydroxycamptothecin, rapamycin, doxorubicin, itraconazole and nimodipine; wherein said liquid solubilizer is selected from the group consisting of liquid polyethylene glycol, polysorbate wherein said good solvent is defined as follows: 1g (ml) of poorly water-soluble drug is capable of being dissolved in less than 30 ml of good solvent for the poorly water-soluble drug; wherein said poor solvent for the poorly water-soluble drug is an aqueous medium; in step i), the mass ratio of poorly water-soluble drug to the protein in step iii) is 1:0.1~15; in step i), the mass/volume ratio of poorly water-soluble drug to liquid solubilizer is 0.1g:0.01~10ml; in step iii), the mass/volume ratio of the poorly water-soluble drug to the poor solvent is 0.1g:1~100ml; wherein said poor solvent has a pH of 5∼8; wherein the method for preparing the protein particle is performed at a temperature of less than or equal to 45°C. wherein said protein is albumin; wherein said poorly water-soluble drug comprises one or more selected from the group consisting of paclitaxel, docetaxel, camptothecin, hydroxycamptothecin, rapamycin, doxorubicin, itraconazole and nimodipine; wherein said liquid solubilizer is selected from the group consisting of liquid polyethylene glycol, polysorbate wherein said good solvent is defined as follows: 1g (ml) of poorly water-soluble drug is capable of being dissolved in less than 30 ml of good solvent for the poorly water-soluble drug; wherein said poor solvent for the poorly water-soluble drug is an aqueous medium; in step i), the mass ratio of poorly water-soluble drug to the protein in step iii) is 1:0.1~15; in step i), the mass/volume ratio of poorly water-soluble drug to liquid solubilizer is 0.1g:0.01~10ml; in step iii), the mass/volume ratio of the poorly water-soluble drug to the poor solvent is 0.1g:1~100ml; wherein said poor solvent has a pH of 5∼8; wherein the method for preparing the protein particle is performed at a temperature of less than or equal to 45°C.