1. participants who refuse to sign informed consent; 2. participants who have other diseases that affect the result, such as trauma, benign and malignant tumors of nasal cavity and paranasal sinuses, intracranial benign and malignant tumors, etc; 3. participants with uncontrolled concurrent diseases that the researcher believes will interfere with the treatment; 4. participants who has contraindications to oral corticosteroids, such as serious gastric and duodenal ulcer, diabetes, glaucoma, etc; 5. participants who have serious neurological or mental diseases, including dementia and seizures; 6.participants who have oral corticosteroids history within 2 weeks, or who have recently taken a large amount of oral corticosteroids and are not suitable after the evaluation of the researcher; 7. participants who have used corticosteroids therapy during the treatment of covid-19 and olfactory function didn't recover; 8. pregnant or lactating women; 9. persons without personal freedom and independent civil capacity; 10. participants who have been enrolled in other intervention clinical trials; 11. participants who with autoimmune diseases; 12. participants who has any situation that may hinder the compliance of the protocol study or the safety during the study; 13. other situations that the investigators think are not suitable for the trial.

1. participants who refuse to sign informed consent; 2. participants who have other diseases that affect the result, such as trauma, benign and malignant tumors of nasal cavity and paranasal sinuses, intracranial benign and malignant tumors, etc; 3. participants with uncontrolled concurrent diseases that the researcher believes will interfere with the treatment; 4. participants who has contraindications to oral corticosteroids, such as serious gastric and duodenal ulcer, diabetes, glaucoma, etc; 5. participants who have serious neurological or mental diseases, including dementia and seizures; 6.participants who have oral corticosteroids history within 2 weeks, or who have recently taken a large amount of oral corticosteroids and are not suitable after the evaluation of the researcher; 7. participants who have used corticosteroids therapy during the treatment of covid-19 and olfactory function didn't recover; 8. pregnant or lactating women; 9. persons without personal freedom and independent civil capacity; 10. participants who have been enrolled in other intervention clinical trials; 11. participants who with autoimmune diseases; 12. participants who has any situation that may hinder the compliance of the protocol study or the safety during the study; 13. other situations that the investigators think are not suitable for the trial.

patients who refuse to sign informed consent; the patient has other diseases that may cause olfactory disorders, such as trauma, benign and malignant tumors of nasal cavity and paranasal sinuses, intracranial benign and malignant tumors, etc. patients with uncontrolled concurrent diseases that the researcher believes will interfere with the treatment; the patient has contraindications to oral corticosteroids, such as serious gastric and duodenal ulcer, diabetes, glaucoma, etc; there are serious neurological or mental diseases, including dementia and seizures; those who have oral corticosteroids history within 2 weeks, or who have recently taken a large amount of oral corticosteroids and are not suitable after the evaluation of the researcher; patients who have used corticosteroids therapy during the treatment of covid-19 and olfactory function didn't recover; pregnant or lactating women; persons without personal freedom and independent civil capacity; those who have been enrolled in other intervention clinical trials; patients with autoimmune diseases; the patient has any situation that may hinder the compliance of the protocol study or the safety during the study; other situations that the researcher thinks are not suitable for the group.

patients who refuse to sign informed consent; the patient has other diseases that may cause olfactory disorders, such as trauma, benign and malignant tumors of nasal cavity and paranasal sinuses, intracranial benign and malignant tumors, etc. patients with uncontrolled concurrent diseases that the researcher believes will interfere with the treatment; the patient has contraindications to oral corticosteroids, such as serious gastric and duodenal ulcer, diabetes, glaucoma, etc; there are serious neurological or mental diseases, including dementia and seizures; those who have oral corticosteroids history within 2 weeks, or who have recently taken a large amount of oral corticosteroids and are not suitable after the evaluation of the researcher; patients who have used corticosteroids therapy during the treatment of covid-19 and olfactory function didn't recover; pregnant or lactating women; persons without personal freedom and independent civil capacity; those who have been enrolled in other intervention clinical trials; patients with autoimmune diseases; the patient has any situation that may hinder the compliance of the protocol study or the safety during the study; other situations that the researcher thinks are not suitable for the group.