Megaloblastic anemia, with causative factors and underlying disease, should be eliminated. The medication used is folic acid treatment, usually an oral preparation, usually 5-10mg, 3 times daily, and people with impaired absorption can switch to the injectable form, calcium tetrahydrofolate 3-6mg intramuscularly, 1 time daily, until the blood picture is completely normalized. Vitamin B12 supplementation therapy with initial vitamin B12, 100ug intramuscularly once daily, can be changed to weekly injections after 2 weeks until blood picture is completely normalized. Patients with nerve involvement can use larger doses, typically 500-1000ug daily; for non-absorptive disorders, equal oral doses can be given at later stages of treatment. If the patient has bleeding, such as in hemophilia, an oral dose may be used. In patients with total gastrectomy or pernicious anemia, vitamin B12 needs to be given intramuscularly at 100ug once a month because the impaired absorption of vitamin B12 is irreversible and requires lifelong maintenance. If the type of vitamin deficiency cannot be determined, folic acid alone is not allowed because supplementation alone can relieve anemia but can exacerbate neurological symptoms and should be combined with folic acid and vitamin B12. Most patients’ blood picture will return to normal within 1-2 months. If the recovery is unsatisfactory, attention should be paid to finding the cause and correcting it, and if iron supplementation is needed, iron supplements can also be given.