Recently, the Department of Hematology of our hospital successfully treated a patient with atypical acute promyelocytic leukemia, a rare clinical condition. The patient, Chen, female, 56 years old, came to our hospital with fever and discomfort. After admission, the routine blood test showed complete blood cytopenia, coagulation function showed extremely low fibrinogen and obvious hyperfibrinolysis, and the laboratory reported a large number of infantile cells in peripheral blood classification. Considering that although APL has the best prognosis among all leukemias, it is often associated with primary hyperfibrinolysis, the greatest risk of bleeding in the early stage of the disease, and a high mortality rate, the patient was given retinoic acid treatment and plasma transfusion and cold precipitation to correct the coagulation disorder to prevent bleeding in a timely manner after perfecting the bone marrow aspiration examination, which gave the patient a chance for further treatment. Both bone marrow cell morphology and flow immunophenotyping returns supported APL, but neither FISH nor PCR methods detected the PML-RARα fusion gene. More than 98% of clinical APL is caused by translocation of chromosome 15 q22 to chromosome 17 q21 resulting in PML-RARα fusion gene and fusion protein. The current first-line induction therapy regimen: all-trans retinoic acid (which specifically acts on the RARα target) combined with arsenic trioxide (which acts on the PML target), can achieve good efficacy. As expected, karyotype analysis showed t(5;17)(q35;q21). Clinically rare t(5;17) APL with no target for the action of the promyelocytic leukemia gene PML on chromosome 15, and arsenic was ineffective. Retinoic acid induction therapy and aggressive symptomatic supportive therapy were continued, and a review of the bone marrow image at 1.5 months of induction therapy showed complete remission.