Objective: To analyze the acute effects of exposure to fine particulate matter (PM2.5) components on primary school students lung function, so as to provide a scientific basis for protecting childrens respiratory health. Methods: From 2019 to 2021, the study selected a total of 2 120 primary school students from grades 3 to 5 in Tianjin using a stratified random sampling method to undergo lung function tests. At the same time, the shortterm exposure levels were simulated by combining PM2.5 components and student addresses, and the acute impact of PM2.5 exposure on primary school students lung function was analyzed by generalized linear models (GLM) and weighted quantile sum (WQS) regression models. Results: The average daily concentration of PM2.5 in the air of Tianjin from 2019 to 2021 was 81.14 μg/m3, which was higher than the national standard. The results of lung function testing showed that there was no statistically significant difference in lung function measurement indicators such as forced vital capacity (FVC), forced expiratory volume at 1 second (FEV1), peak expiratory flow (PEF), 75% forced expiratory volume in 75 (FEF75), and 25% forced expiratory volume in 25 (FEF25) among primary school students in different regions of Tianjin (F=1.23, 0.87, 2.34, 1.56, 0.98, P>0.05). But the GLM analysis results showed that all components of PM2.5 in the air had adverse effects on the lung function indicators of primary school students. When the concentrations of fluorene (FLU) and pyrene (PYR) increased by 10 ng/m3, the FVC of primary school students decreased by 166.44 and 61.94 L respectively. The WQS regression model analysis results showed that the mixed exposure of PM2.5 components particularly significant damaging effects on lung function indicators in primary school students, especially the FLU and PYR components in polycyclic aromatic hydrocarbons, as well as the heavy metal lead. Conclusions Both single and mixed exposure to various PM2.5 components in the air have adverse effects on the lung function of primary school students. Among them, the influences of FLU and PYR in polycyclic aromatic hydrocarbons, as well as heavy metal Pb, are particularly significant.Potential pollution sources should be controlled to protect the respiratory health of primary school students by comprehensive prevention and control measures.