The present invention relates to a protein particle with a poorly water-soluble drug encapsulated therein and a preparation method therefor. The preparation method comprises 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); iii) mixing the product of step ii) with a protein; and iv) dispersing the product of step iii) in a poor solvent. The preparation method is simple and is suitable for industrial production.