The invention discloses a novel method for a drug loading system constructed by means of sensitization blood platelets for treating immune thrombocytopenia. The method comprises the steps that firstly, whole blood is anti-coagulated and centrifuged to obtain platelet rich plasma, then, deep centrifuging washing is performed to obtain washed platelets, the washed platelets react with CD41 monoclonal antibody oscillation, and centrifuging is performed to obtain the CD41 monoclonal antibody modified target macrophage sensitization blood platelets; then, the sensitization blood platelets and an immunosuppressor or a chemically modified cytotoxic drugs are mixed and incubated, centrifuging and purifying are performed, and finally the sensitization blood platelet drug loading system carrying drug for resisting immune thrombocytopenia is obtained. The drug loading system has the advantages of being abundant in source, high in drug loading rate, good in biocompatibility, high in targeting, long in cycle time and the like, the drug can precisely target macrophage, and the concentration of the drug inside the macrophage is increased, so that the drug curative effect is improved, and meanwhile the toxic and side effect on normal tissue is effectively relieved.