Objective To explore the effect of cold-warm cycle stimulation on nasal mucosal immune barrier function in rats and determine the difference between Mahuang decoction and Yinqiao powder, which are commonly used in traditional Chinese medicine. Methods For cold-warm cycle stimulation, SD rats were exposed to four cycles of -15°C for 1 hour and then 25°C for 30 minutes. At different time points after the last stimulation, the protein expression of IgA in the nasal mucosa was detected by Western blot. Seven days after the first cold-warm cycle stimulation, the rats were re- subjected to cold-warm cycle stimulation under the same conditions. The dynamic changes in IgA protein expression in the nasal mucosa, lysozyme and prostaglandin E2 (PGE2) levels in nasal lavage fluid and PGE2, TNF-α, IL-6 and IL-1β serum contents were detected on days 1 ~ 11 after the last stimulation. The rats were randomly divided into negative control, model, Mahuang decoction and Yinqiao powder groups. After repeated cold-warm stimulation for 6 hours, the rats in the negative control group and model group were given distilled water, the Mahuang decoction group was given 2. 43 g crude drug / kg body weight Mahuang decoction, and the Yinqiao powder group was given 16. 74 g crude drug / kg body weight Yinqiao powder once a day for 7 days 30 minutes after the last stimulation. Except for the negative control group, the other groups were re-subjected to repeated cold-warm stimulation, and the medicines were given twice at 6 and 22 hours after stimulation. Nasal lavage fluid was prepared, nasal mucosal tissue was extracted, and blood was obtained for detecting the corresponding indexes at 24 hours. Results After repeated cold-warm cycle stimulation, IgA protein expression in the nasal mucosa was significantly decreased at days 1 and 3 and then gradually increased and returned to normal on day 7. When rats were re-stimulated by cold-warm cycles, IgA protein expression in the nasal mucosa was significantly decreased, and the amounts of lysozyme and PGE2 in nasal lavage fluid were significantly decreased on days 1 and 3. The serum level of TNF-α remained high, and the contents of PGE2 and IL-1β were significantly increased on days 1 and 3. In contrast, the IL-6 content only increased on day 1 after stimulation. Both Mahuang decoction and Yinqiao powder interventions increased IgA protein expression in the nasal mucosa and sIgA content in nasal lavage fluid. Yinqiao powder also increased the amount of lysozyme in nasal lavage fluid and decreased the serum contents of TNF-α and IL-1β. Conclusions Repeated cold- warm stimulation decreases the function of the nasal mucosal immune barrier and increases the release of several types of inflammatory factors in rats. Mahuang decoction and Yinqiao powder improve the function of the nasal mucosal immune barrier. Mahuang decoction increases the IgA content, and Yinqiao powder reduces inflammatory factors to a greater extent.