A female, 31-year-old patient was admitted a few days ago, with weakness and abdominal distension in the last six months. No other symptoms. Physical examination: emaciation, no enlargement of lymph nodes, abdominal bulge, large liver, large spleen, giant spleen 25 cm below the pelvic rib cage. Examination: WBC 680 X 10(9) Hb 90 g/l PLT 226 X 10(9) Previous: The patient had a WBC of 150 X 10(9) one year ago when she was pregnant and continued to increase, which was not treated at that time. The patient was admitted to the hospital for “hypersplenism” and was prepared for spleen surgery. A clinical diagnosis of CML (chronic granulocytic leukemia) was made and a bone marrow biopsy, bone marrow smear cytology, and peripheral blood smear cytology were performed. BCR/ABL fusion gene testing was performed. Diagnosis of CML was confirmed. Treatment: Hydroxyurea for hyperleukocytosis. Imatinib TKI targeted therapy. Several brothers of the patient did tissue matching for hematopoietic stem cell transplantation. Progressive improvement of disease. Discussion: 1,, Splenomegaly, the cause needs to be identified in order to treat the cause. It is easy to go wrong with headache treatment. 2, In case of malignancy during pregnancy, if it is CML, the chronic phase can be taken to wait and observe. If the WBC is 100×10(9), it needs to be treated in the accelerated phase of treatment (avoid teratogenic drugs such as Imatinib, hydroxyurea, etc., immediate specialist consultation).