The new coronavirus has been present for two years and has had a widespread and sustained impact worldwide. There is growing evidence in the literature that COVID-19 may have negative effects on mental illness in patients and in healthy populations. The unprecedented changes brought about by COVID-19, such as social isolation, school closures, and family stress, negatively affect people's mental health, especially that of children and adolescents. The purpose of this paper is to review the literature and summarize the impact of COVID-19 disorders on children's and adolescents' mental health, the mechanisms and risk factors, screening tools, and intervention and prevention. We hope that the mental dysfunction caused by the pandemic will be mitigated through appropriate and timely prevention and intervention.