Child maltreatment among children in the welfare system is associated with multiple risk factors, including family structure changes, parental health problems, and limited access to intervention services. However, few studies have explored the association between multidimensional poverty and child maltreatment. The objective of this study is to examine the victimization profiles of children in the welfare system of China and the associations of those profiles with multidimensional poverty. A total of 210 welfare system-involved children in China aged 8 to 16 years participated in the survey conducted in 2022 and were asked about their maltreatment experiences and multidimensional poverty. Descriptive analyses and binary logistic regressions were performed. An alarming percentage (78.1%) of the surveyed children reported experiencing maltreatment in the preceding year. After controlling for significantly associated factors (sex, parental adversity, caregiver/guardian health), multidimensional poverty was significantly associated with increased odds of emotional abuse (OR = 5.058, p < 0.001), physical abuse (OR = 10.76, p < 0.001), emotional neglect (OR = 2.991, p < 0.001), physical neglect (OR = 10.678, p < 0.001), and multiple types of maltreatment (OR = 13.799, p < 0.001). The findings show that the child multidimensional poverty approach is effective and practical in predicting children at high risk of maltreatment, particularly among children in the welfare system. It is essential to reduce deprivation among children in terms of their multidimensional needs. In addition to traditional cash transfers, comprehensive welfare services to protect children from maltreatment are needed in child and family policies.