This study is based on trilingual acquisition and explores the influence of parental education and a trilingual environment through a case analysis of children's language acquisition in Salar families. The mother language (L1) is Salar, the second language (L2) is Mandarin, and the third language (L3) is English. The children's acquisition of three languages and the acquisition process in a trilingual environment and family education were explored deeply through observation and interviews. The study results show that children are more likely to acquire the three languages in a trilingual environment. However, relying only on family education without providing a trilingual environment makes it generally more difficult for children to acquire three languages than in a trilingual environment.