The invention relates to the technical field of medical instruments, and provides a blood smear staining method and a blood smear staining box. The blood smear staining method comprises the following steps: a, putting a blood smear in a box; b, injecting a cell pre-immobilization staining solution into the box so as to perform cell pre-immobilization on the blood smear; c, discharging the cell pre-immobilization staining solution in the box; d, blowing air into the box to dry the blood smear; and e, injecting a staining solution into the box to stain the blood smear. The provided blood smear staining box comprises a box body for accommodating the cell pre-immobilization staining solution, the staining solution or clear water and also for accommodating the blood smear, an injection needle for injecting the cell pre-immobilization solution, the staining solution or clear water, a liquid-discharging needle for discharging the liquid in the box body, and an air-blowing needle for blowing air into the box body to dry the blood smear. The blood smear staining method is capable of simplifying the structure of the staining device, reducing staining flow and also improving the staining efficiency.