Preparation method of stable protein drug-loaded microparticle system

The invention provides a preparation method of a stable protein drug-loaded microparticle system. The system can be used in a protein microparticle system to deliver a drug into body in order to perform the curative effect. The preparation method comprises the following steps: 1, mixing an organic phase containing the drug with a water phase containing proteins by using a bridging agent to form a homogeneous solution; and 2, directly freeze-drying the homogeneous solution at 0-80DEG C to form a freeze-dried powder injection preparation, carrying out compatibility dilution by using 5% glucose or normal saline or other diluents in clinic use to form the stable protein drug loaded particle; or rapidly diluting the homogeneous solution to reduce the concentration of the bridging agent in order to make the drug rapidly embedded by the proteins and assembled to form the microparticle system. The stable protein drug loaded microparticle system can be used to deliver the drug into body in order to perform the curative effect. The method for preparing the stable protein drug-loaded microparticle system by using the bridging agent has the advantages of mild and simple conditions, suitableness for industrialization, and good application prospect.