Chronic maxillary sinusitis is caused by long-term inflammation of the maxillary sinus, and its symptoms may include nasal congestion, pus flow, headache, etc. Hypertrophy of the inferior turbinate can be seen on examination of the nasal cavity, purulent secretions can be seen in the middle nasal passage, and the diagnosis can be confirmed by sinus CT showing high-density shadows in the nasal cavity. Treatment is divided into conservative treatment and surgical treatment. Conservative treatment mainly consists of oral antibiotics, usually with a small dose of clarithromycin for 2-3 months, nasal spray of tretinoin, and nasal rinsing with 3% hypertonic saline in the nasal cavity. If the above conservative treatment is ineffective or the effect is not obvious, surgical treatment can be adopted, and nowadays, most of them use nasal endoscopic sinus open surgery, strengthen the dressing change after surgery, and follow up for at least 6 months, and the nasal cavity still needs to spray tretinoin for 1-3 months.