⁃ Aged 18 \

• 70 years old (including boundary value), regardless of gender;

⁃ FLT-3 positive acute myeloid leukemia;

⁃ The expected survival time was more than 3 months;

⁃ ECOG score 0-2;

⁃ Refractory or relapsed AML patients after standardized treatment who meet any of the following criteria:

∙ After complete remission (CR), there were ≥5% leukemia cells or blast cells in the bone marrow(except for other reasons such as bone marrow regeneration after consolidation chemotherapy)in the peripheral blood and extramedullary lesions;

‣ Naive patients who are treated with 2 courses of treatment and are ineffective;

‣ Those who have relapsed within 12 months after CR after consolidation and intensive treatment;

‣ Those who relapse after 12 months but are ineffective after conventional chemotherapy;

‣ Subjects who experienced relapses twice or multiple times; with persistent extramedullary leukemia.

⁃ Kidney function, cardiopulmonary function, liver function, and coagulation function meet the following requirements:

∙ Creatinine ≤ 1.5 ULN;

‣ Left ventricular ejection fraction ≥ 50% and echocardiography does not reveal pericardial effusions and ECG does not reveal clinically significant abnormal bands;

‣ Blood oxygen saturation \> 92%;

‣ Total bilirubin ≤ 2 × ULN; ALT and AST ≤ 2.5 × ULN; for the patients with ALT and AST abnormalities caused by disease which researchers judge (e.g. liver infiltrates or bile duct obstruction), the indicators of which can be relaxed to ≤5× ULN;

‣ PT/INR and PTT ≤ 1.5 ULN;

⁃ Patients understand the trial and have signed the informed consent form.