Objective To investigate the mental behavior problems of preschool children in Taihu County and its influencing factors. Methods Stratified cluster sampling method was used to select kindergartens in Taihu County.The Conners parental scale was used to investigate the mental behavior problems of children.EpiData 3.1 software was used for data entry,and SPSS 17.0 software was used for statistical analysis.Multivariate logistic regression analysis was used to analyze the factors affecting the mental behavior problems of preschool children. Results A total of 1 001 children were investigated,among which 213 children were found to have various mental behavior problems,with a detection rate of 21.28%.Univariate analysis showed that there were statistically significant differences in the detection rates of mental behavior problems among children with different gender (χ²=23.013,P＜0.001),age (χ²=17.686,P＜0.001) and parents' migrant work situation (χ²=5.055,P=0.025).Multivariate logistic analysis showed that male (OR=2.215,95%CI:1.590-3.084) and one or both parents working outside the home (OR=1.480,95%CI:1.077-2.034) were risk factors for mental behavior problems in preschool children. Conclusion There is a high detection rate of mental behavior problems in preschool children in Taihu County.Parents working outside the home affects the mental behavior health of preschool children.