A retrospective study from 2008 to 2019 examined the effect of PM2.5 fine particles from forest fires on respiratory disease in Chinese children and adolescents aged 4 to 24 years. The research included 6,089,271 cases of respiratory illness and 1,034 deaths in 501 cities. The findings showed that each 5 μg/m³ increase in wildfire-related PM2.5 was associated with a 6.8% increase in the daily incidence rate of respiratory disease, significantly higher than the 0.2% increase in non-fire-related PM2.5. PM2.5 from wildfires was associated with a 28.6% increase in tick season cases, a 5.2% increase in fever, a 12.6% increase in rubella and a 13.6% increase in measles. Although PM2.5 from forest fires accounts for only 2.7% of total PM2.5, it accounts for 10.8% of all PM2.5-related respiratory disease cases. An increased risk of respiratory diseases was also observed in areas with lower concentrations of PM2.5 from forest fires, where the proportion of cases reached 29.7%. The authors conclude that short-term exposure to PM2.5 from forest fires poses a significantly greater health risk for children and adolescents than other sources of PM2.5.