In addition to their regular teaching responsibilities, substitute teachers also have to manage their own self-promotion and handle complaints, which leads to a heavier workload compared to permanent teachers. This study focuses on 285 substitute teachers in School H, and utilizes the statistical analysis tool spss18.0 to demonstrate that the transactional, relational, and developmental dimensions of the substitute teachers' psychological contracts are significantly and negatively related to their intention to leave (p < 0.05). Furthermore, multiple linear regression shows that the developmental dimension of the psychological contract has the greatest impact on the intention to leave. Finally, the paper provides recommendations for optimizing human resource management in private schools.