Disclosed are uses of drugs for treating thrombocytopenia, in particular the use of dencichine in preparation of drugs for treating thrombocytopenia. By adding pharmaceutically acceptable conventional adjuvant material, dencichine can be prepared into an oral preparation or an injection. A pharmacodynamic trial shows that the dencichine can effectively inhibit the thrombocytopenia caused by chemotherapy drugs, and treat thrombocytopenic purpura with obvious curative effect and low toxic side effects.