Background To date, no national-scale psychiatric epidemiological survey for children and adolescents has been conducted in China. In order to inform government officials and policymakers and to develop a comprehensive plan for service providers, there was a clear need to conduct an up-to-date systematic nationwide psychiatric epidemiological survey. Methods We conducted a two-stage large-scale psychiatric point prevalence survey. Multistage cluster stratified random sampling was used as the sampling strategy. Five provinces were selected by comprehensively considering geographical partition, economic development, and rural/urban factors. In Stage 1, the Child Behavior Checklist was used as the screening tool. In Stage 2, Mini-International Neuropsychiatric Interview for Children and Adolescents and a diagnostic process based on the Diagnostic and Statistical Manual were used to make the diagnoses. Sampling weights and poststratification weights were employed to match the population distributions. Exploratory analyses were also performed using socio-demographic factors. Prevalence in socio-demographic factor subgroups and overall were estimated. Rao-Scott adjusted chi-square tests were utilized to determine if between-group differences were present. Factor interactions were checked by logistic regression analyses. Results A total of 73,992 participants aged 6-16 years of age were selected in Stage 1. In Stage 2, 17,524 individuals were screened and diagnosed. The weighted prevalence of any disorder was 17.5% (95% CI: 17.2-18.0). Statistically significant differences in prevalence of any psychiatric disorder were observed between sexes [chi(2)(1, N = 71,929) = 223.0, p < .001], age groups [chi(2)(1, N = 71,929) = 18.6, p < .001] and developed vs. developing areas [chi(2)(1, N = 71,929) = 2,129.6, p < .001], while no difference was found between rural and urban areas [chi(2)(1, N = 71,929) = 1.4, p = .239]. Male, younger individuals, children, and adolescents from developed areas had higher prevalence of any psychiatric disorder. The prevalence of any psychiatric disorder was found to decrease with the age in the male group, while the female group increased with the age. Individuals diagnosed with attention-deficit hyperactivity disorder, oppositional defiant disorder, a tic disorder, conduct disorder, and major depression disorder had the highest rates of comorbidity. Conclusions The prevalence of any psychiatric disorder we found is the highest ever reported in China. These results urgently need to be addressed by public mental health service providers and policymakers in order to provide access to the necessary treatments and to reduce the long-term negative impact of these conditions on families and the society as a whole.