Platelet 49×10^9/L after playing interferon is mainly due to the adverse reaction of the drug, which should be taken timely to avoid danger. Interferon has anti-tumor, anti-viral and immunomodulatory effects, and can be used to treat warts, flat warts, genital herpes, chronic active hepatitis B and other diseases. However, there are some adverse effects associated with interferon use, such as rash, insomnia, anxiety, cardiac arrhythmia, etc.; if the course of medication is prolonged, it may lead to bone marrow suppression, which may result in adverse manifestations, such as thrombocytopenia, leukopenia, and anemia. In addition, interferon is contraindicated in patients with severe hepatic and renal impairment and allergy to the product. Platelets 49×10^9/L after interferon injection can be replaced with other antiviral drugs and some platelet-raising drugs, such as recombinant human thrombopoietin and aminopterin. Platelet 49×10^9/L after playing interferon should pay attention to the correct treatment under the guidance of the doctor, and avoid stopping the drug privately, so as not to affect the treatment of the condition.