Low fluorescence intensity reticulocyte ratio should be checked to see if there is a lack of hematopoietic materials such as iron, folic acid and vitamin B12 in the peripheral blood. Low fluorescence reticulocytes represent mature reticulocytes, and the decrease of their ratio indicates the increase of naïve reticulocytes, i.e., the whole red blood cell system is naïve, and the maturity is reduced, which shows that the bone marrow is active in hematopoietic function, but due to the lack of hematopoietic raw materials or inability to utilize the causes of hemorrhagic anemia, and the content of red blood cells and hemoglobin can be restored after supplementing hematopoietic raw materials or treating the primary disease. The key of anemia treatment is to find the cause of the disease and treat the primary disease. In addition to routine blood test, it is also necessary to combine with other tests, such as bone marrow test if necessary.