<p>Recent studies have shown a close correlation between air pollution and the occurrence of asthma. A distributed lag nonlinear model was used in this research to analyze the relationship between 58,610 asthma outpatient hospital visits and daily PM_2.5, PM₁₀, NO₂, SO₂, CO, and eight hour mean O₃ exposure from 4 hospitals in Xinxiang City, Henan province from January 1, 2016 to December 31, 2021, and a stratified analysis of gender and age were conducted. Results showed that low concentrations of daily PM_2.5 (40&#xa0;µg/m³), PM₁₀ (20 and 80&#xa0;µg/m³), CO (0.8 mg/m³), NO₂ (10–30&#xa0;µg/m³) and SO₂ (15&#xa0;µg/m³) exposure reduced the number of outpatient visits for asthma patients. High levels of daily PM_2.5 (50–100&#xa0;µg/m³), PM₁₀ (100–140 and 820&#xa0;µg/m³), and SO₂ (20–25&#xa0;µg/m³) exposure increased the number of outpatient visits for asthma patients. Both low (15–60&#xa0;µg/m³) and high (150–205&#xa0;µg/m³) concentrations of the eight hour mean O₃ exposure increased asthma outpatient hospital visits. Gender-stratified analysis revealed that, for male asthma patients, the daily outpatient visits decreased when CO exposure concentration of 0.8 mg/m³; while for female asthma patients, the daily outpatient visits decreased when SO₂ exposure concentration of 15&#xa0;µg/m³, but increased when the concentration was 20&#xa0;µg/m³. In comparison, both low and high concentrations of eight hour mean O₃ exposure increased the daily male asthma outpatient hospital visits. Additionally, when the eight hour mean O₃ exposure concentration was 10–30&#xa0;µg/m³ and the daily SO₂ exposure concentration was 20&#xa0;µg/m³, asthma outpatient hospital visits for adult increased; when the eight hour mean O₃ exposure concentration was 145–220&#xa0;µg/m³ and the daily SO₂ exposure concentration was 50–110&#xa0;µg/m³, asthma outpatient hospital visits for adolescent increased. This study suggests that asthma patients should limit going outdoors on days with poor air quality, especially for women and adolescents.</p>