If there is no obvious clinical manifestation and hemodynamic abnormality, usually no treatment is needed; if there is indication for treatment, treatment is needed. Oval foramen not closed with a separation gap of 3.3㎜ belongs to the moderate category of oval foramen not closed. If there is no obvious blood shunt after thorough examination and no clinical manifestations, active treatment is usually not necessary, and only regular clinical follow-up is needed. However, it should be noted that if the patent foramen ovale is not closed and there is an unexplained stroke or transient ischemic attack without surgical indication, medication can be administered, including antiplatelet therapy with aspirin, clopidogrel and other drugs to prevent thrombosis. However, these drugs need to be administered under the guidance of a clinician and unauthorized use is prohibited. In the case of unexplained stroke or transient ischemic attack combined with patent foramen ovale, but not suitable for antiplatelet therapy; or the use of antiplatelet or anticoagulant therapy but still have a recurrence of stroke and other diseases; unexplained stroke or peripheral embolism combined with patent foramen ovale, with thrombus on the surface of the right heart or implanted devices, and so on, it is recommended to carry out surgical intervention. In the presence of patent foramen ovale non-occlusion with a separation gap of 3.3㎜, it is recommended to go to the hospital in a timely manner and make recommendations for diagnosis and treatment after the clinician evaluates the condition.