Language is the most important communication tool for human beings, the acquisition of vocabulary lays the foundation for the development of children's language, children's mastery of vocabulary is an important standard to judge the level of language development. PPVT test was conducted among 153 migrant preschool children in 5 kindergartens in N City, and questionnaires were sent to their teachers and parents. We found: the migrant children's vocabulary mastery of different types is unbalanced, the level of mastering increases with age, the effect of on the vocabulary is significant, there is significant effect of the quantity of family books and family cultural activities and the application of toys in kindergarten and the teacher-child conversation on the vocabulary development of migrant preschool children. As for improving the vocabulary ability of migrant children,we should play the foundation role of family education, and made up the shortage of vocabulary development by high-quality kindergarten education.