Delta virus is a mutated novel coronavirus strain, and the sequelae that appear after the infection has healed are still short and await further follow-up. The following sequelae have been found in patients with novel coronavirus pneumonia infected with Delta virus strain, but it is inconclusive whether they are permanent. 1. persistent cough: after some patients recovered, the symptoms of cough were prolonged, and it is necessary to continue to follow up and observe whether the cough symptoms will persist for a long time. 2. loss of smell and taste: some patients had loss of smell and taste during the onset of the disease, but after the disease recovered Some patients still have smell and taste dysfunction several months after recovery, and it remains to be observed whether it will become a permanent sequelae. Some patients even affect their daily life and work; 5. Insomnia, depression: some patients have insomnia, resulting in lack of sleep and poor sleep quality, and even need auxiliary tranquilizers to fall asleep, and some patients have depression; 6. Pulmonary fibrosis: some patients with severe pneumonia have pulmonary fibrosis after recovery, which affects lung function, and some are accompanied by long-term cough; 7. Others: some patients may develop femoral head necrosis, which is usually related to the hormonal drugs used. Delta virus is a new mutant strain that has emerged in recent years, and the research on its sequelae is still immature, and it is not yet possible to judge how long the above sequelae will continue. It is also possible that other new sequelae will be identified in subsequent observations, and that the delta virus has a significantly greater ability to spread and spread faster compared to other strains. Therefore, it is important to practice the habit of washing hands regularly and wearing a mask when going out.