Objective: To explore the relative risks of rotavirus diarrhea after exposure to different levels of atmospheric pressure in children in Guangzhou City, so as to provide reference for improving public awareness of high atmospheric pressure exposure. Methods: The study used the China Notifiable Communicable Diseases Network System and China Meteorological Science Data Sharing Service Network to collect meteorological data and data relating to daily cases of rotavirus diarrhea in children at Guangzhou Women and Children s Medical Center from 2012 to 2020. The association between rotavirus diarrhea and atmospheric pressure was analyzed using distributed lag non linear models (DLNM). The relative risks of different sex and age sub groups exposed to different atmospheric pressures were also evaluated. Results: A total of 18 587 cases of rotavirus diarrhea were reported from 2012 to 2020, among which 11 662 cases (62.7%) were boys, and 12 582 cases (67.7%) were children aged 6 to 24 months old, which represented the highest proportion. The results of the DLNM showed that the relative risk of rotavirus diarrhea was the highest on the day of exposure to extreme high atmospheric pressure ( RR =1.50, 95% CI =1.24-1.82, P <0.05) and the effect could last for 28 days. Risk of rotavirus diarrhea was low for exposure to low pressure within 2 weeks ( P <0.05). During extremely high atmospheric pressure weather, RR was higher in girls ( RR =3.31, 95% CI =1.46-7.49， P <0.05) than that in boys ( RR =1.98, 95% CI =0.96-4.07， P >0.05). Among different age sub groups, RR was the highest in children aged 24 to 60 months after exposure to the highest level of atmospheric pressure exposure ( RR =3.36, 95% CI =1.27-8.89, P <0.05). Conclusion In Guangzhou, exposure to high pressure increases the risk of rotavirus diarrhea in children. In the future, public awareness should be raised regarding the risk after exposure to high atmospheric pressure.