Abstract: There is still an obvious gap in the development of education between eastern and western China. It is important to explore the key factors influencing teachers' subjective well-being and the mechanism among the factors, which can improve the quality and stability of the teaching staff and promote the development of education modernization. The survey was conducted in Qinghai Pro-vince, China. Based on the job demands-resources model and conservation of resources theory, a Structural equation modeling(SEM) analysis was conducted by using a sample of 1623 teachers in compulsory education from Qinghai Province to reveal the effect of social support from colleagues on teachers' subjective well-being and the mechanism of the effect. The result shows that social support from colleagues has a positive effect on teachers' subjective well-being, and "teaching efficacy→teachers' resilience" has a significant chain mediation effect, in which teachers' resilience plays a key role. Social support from colleagues is not only directly related to teachers' subjective well-being, but also enables teachers to recover faster in adversity or stressful situations, cope better with events, and devote themselves to teaching.Social support from colleagues can make teachers more confident that they are able to achieve the expected educational and teaching goals, encourage them to stay strong and positive, and eventually contribute to the enhancement of teachers' subjective well-being.