Combined with the introduction of a case, the clinical experience of Professor Yan Shiyun in differential treatment of refractory relapsed acute myeloid leukemia secondary to granulocytic sarcoma is analyzed. It is considered that its pathogenesis is a febrile disease caused by latent pathogenic factors. And with syndrome differentiation of Weiqi Yingxue, Bagang and Zang-fu organs, the disease is treated with the method of combining disease and syndrome differentiation guided by the core idea of “strengthening healthy qi to eliminate pathogenic factors with flexible methods through fully grasping the pathogenesis”. Professor Yan Shiyun is adept at using empirical medicines and drugs with drastic or toxic actions, and prescribes Niuhuang Xingxiao pill to control the proliferation of leukemic cells.