Domestic violence, separation and divorce are becoming increasingly common and leaving psychological traumas that are not easily healed for family members, especially for children in Vietnamese incomplete family. In this article, we identify the factors affecting the psychological trauma of children in the incomplete families by using Achenbach T. M's Children Behavior Checklist (CBCL). We design 2 experiments and 3 steps to filter the main factor affected the psychological trauma of children living in incomplete families. In results, we found out that up to 46.42% of children had psychological traumas when living in incomplete family with an extremely high level of 8.16% and an average of 57.14%. The results showed not only by living in incomplete family but also other factors such as the pressure from public opinion and community affected the children psychological trauma. It is necessary to minimize the effect of psychological trauma of children in Vietnamese families.