Second relapse of leukemia can be treated with combination chemotherapy or bone marrow transplantation, but the treatment difficulty is significantly increased. 1. The second relapse of leukemia belongs to refractory relapsed leukemia, and it is necessary to re-examine the condition by bone marrow aspiration, bone marrow biopsy and fusion gene, and then formulate the induction chemotherapy plan according to the examination results to re-induce chemotherapy, and some patients can achieve remission, and then carry out intensive consolidation and maintenance chemotherapy, and also bone marrow transplantation is also feasible. 2. For patients with second relapse of leukemia, the treatment difficulty is obviously increased, and some of them have difficulty in achieving remission again, for these patients, salvage bone marrow transplantation can also be tried. For patients who fail induction chemotherapy or cannot undergo bone marrow transplantation, only supportive treatment can be given, such as active anti-infection (levofloxacin), red blood cell transfusion, platelet transfusion and so on. Specific chemotherapeutic drugs include cytarabine, hypertriglycerides, decitabine, and vinacrine. It is recommended that the patient should visit the Department of Hematology in time, and the specialist should formulate individualized treatment plan according to the patient’s condition and actively treat the patient.