As a non-invasive and reversible conservative treatment method that addresses the fear of surgery, the oral appliance is mainly applied in the comprehensive, sequential treatment of snoring, upper airway resistance syndrome, patients with mild to moderate obstructive sleep apnea and patients with severe obstructive sleep apnea. It is particularly suitable for snoring patients who do not have an indication for surgery or do not want to be treated surgically and who cannot tolerate positive pressure ventilation (CPAP) therapy, or in combination with ventilation therapy as a treatment tool when traveling.