Diffuse midline glioma with H3K27M mutation is a new tumor type of WHO central nervous system tumor classification. It often occurs in the midline structure and usually has a poor prognosis. A 38-year-old male patient presented with 2 years history of right limb with facial numbness, tumors in the left thalamic region and lateral ventricle was detected by imaging. The patient underwent the first surgery. The pathological examination results: Glioblastoma. He recovered well after surgery and received a total of 30 times of radiotherapy and temozolomide for one year. Fourteen months later, tumours were observed in the left thalamic region and left parieto-occipital lobe, the patient underwent the second operation. Immunohistochemistry showed: H3K27M(+). He experienced limitation of right limb movement after surgery and started taking oral apatinib 250 mg qd. After one-year, multiple tumors were found in the left brainstem, bilateral ventricles, bilateral basal ganglia, etc. The patient was given radiotherapy 7 times and then took apatinib 250 mg qd. Now the patient is still alive. H3K27M mutant diffuse midline glioma is characterized by diffuse infiltrative growth. Its pathological classification is diverse, imaging features lack specificity, and prognostic factors are complex. Traditional radiochemotherapy has limited effects, molecular targeted therapy, especially intervention of epigenetic regulation is being explored.