Body experiences and conditions bear close relations to social development and human well-being. However, no consensus has been reached regarding the impact of coronavirus disease 2019 on negative body image. Investigating a reliable relationship between COVID-19 and negative body image, we developed a dictionary of negative body image to obtain panel data on body image for 31 Chinese provinces/municipalities/autonomous regions. We compared negative body image before and after the pandemic and explored the impact of pandemic severity. The prevalence of negative body image decreased following the outbreak and remained at a relatively low level for two years. After controlling regional and temporal effects, we verified epidemic severity as an important predictor of the decline in negative body image. The findings suggest that the public is likely to accept their physical appearances during lockdown due to changes in lifestyle and the fear of mortality. This research has important implications for gaining insights into the dynamic transformation of public negative body image under the influence of catastrophic public health events.