Children’s leukemia starts sharply, and there are non-specific symptoms in the early stage, such as low appetite, laziness, fatigue, pain in limbs and other symptoms of the main clinical symptoms. The main symptoms are: 1, fever, fever type is irregular, can be low fever, can also be high fever, mostly related to tumor fever, can be accompanied by infection, the common site of infection is seen in the respiratory tract, followed by subcutaneous mucous membranes. 2, anemia is the most common with pallor, with the aggravation of the disease, the prolongation of the disease, the emergence of symptoms of severe anemia, such as fatigue, dizziness, shortness of breath after activity. 3, bleeding is common with the bleeding of the subcutaneous mucous membrane. . There are purpura, ecchymosis, petechiae of the skin, and gum bleeding, nasal bleeding can also be seen, and some patients with acute promyelocytic leukemia can be combined with intracranial hemorrhage, which is more dangerous.4. Leukemia cells infiltrate organs, and the main organs are superficial lymph nodes and liver and spleen, which can lead to obvious enlargement. Infiltration of bone marrow can appear bone pain, arthralgia symptoms, bone pain manifested as sub-sternal pressure pain, arthralgia is usually a wandering joint pain as the main manifestation. Infiltration of the testes can lead to painless enlargement of the scrotum on one side, and the surface of the scrotum is reddish-black. Infiltration of the central nervous system can present with headache, vomiting, impaired consciousness and other manifestations of increased intracranial pressure. It can also infiltrate the skin with subcutaneous nodules, the digestive and urinary systems or the heart, leading to a number of associated symptoms.