Background: Children and adolescents are in the developmental periods with the highest risk of experiencing multiple types of traumatic experiences (TEs). Immigrant children are more likely than other children to be exposed to TEs and have a higher risk of mental health problems. However, no epidemiological study has reported the prevalence of TEs and the associated development of posttraumatic stress disorder (PTSD) among Chinese children. Methods: The present study focused on trauma exposure among rural-to-urban migrant Chinese children. A large-scale (N = 16,140) cross-sectional survey of rural-to-urban migrant workers' children in grades 4 to 9 was conducted in Beijing. Lifetime exposure to accidents and injuries, interpersonal violence, and trauma within the social network or witnessing traumatic events were measured along with PTSD. Results: Nearly half of the participants (47.06%) had experienced TEs, and 6.68% of those children met the cutoff for PTSD. Trauma exposure was associated with gender, age, quality of life, parents' marital status, caregivers before the child started school and father's education level. Overall, interpersonal violence was associated with the highest rates of PTSD, and disasters were associated with the lowest rates of PTSD. Limitations: The cross-sectional survey design limited the ability to document temporal ordering, and the assessment of lifetime TEs was based on retrospective recall. Conclusions: The present study is the first epidemiological study of TEs in Chinese rural-to-urban migrant children. TEs are potentially fairly common among this population. Interventions designed to prevent PTSD should target different TE types according to the victim's gender.