There are many types of blood tests for childhood leukemia. Children’s leukemia is divided into acute lymphoblastic leukemia and acute myeloid leukemia, the performance of children with leukemia is mainly in the following areas: 1, the number of white blood cells can be elevated, high leukocyte leukemia can rise to very high, such as normal is 4000-10000 × 10^6 / L, this type of children may be as high as 100000 × 10^6 / L, 200000 × 10^6 / L ×2. Hemoglobin may decrease to different degrees, i.e., it may show mild anemia, moderate anemia, or even severe anemia or very severe anemia; 3. Platelets tend to decrease to different degrees, and 4. abnormal naïve cells may be found in peripheral blood smears. In the case of acute lymphoblastic leukemia, abnormal lymphocytic leukemia cells may be found, and in the case of myeloid leukemia, there may be an increased proportion of granulocytes and very high levels of abnormal neutrophils. A peripheral blood smear may reveal naïve granulocytes.