It is very dangerous to have 3 x 10⁹/L platelets left after chemotherapy. Chemotherapy is a very important means of treating tumors, but chemotherapy may cause a drop in white blood cells and platelets. Hemostasis is the main function of platelets, and if the index is lower than 5×10⁹/L, at this point, it is in a very dangerous situation, and subcutaneous or visceral bleeding or intracranial bleeding may occur. Moreover, once bleeding occurs, it is very difficult to stop bleeding, and systematic platelet-boosting therapy must be carried out, and platelet transfusion is necessary to replace the missing platelets. Specific hemostatic drugs include tranexamic acid, snake venom hemagglutinin, etc., and platelet-boosting drugs include eltrombopagide, human thrombopoietin, etc. During the period of chemotherapy, blood routine should be closely monitored to prevent low platelets from affecting the safety of life, and the specific treatment should be carried out under the guidance of physicians.