Off-site construction (OSC) has been actively promoted in many countries, but it has not become the mainstream in Chinese construction industry due to various obstacles. As a new innovation construction method, the critical factors and driven routs for promoting OSC should be explored in this stage. This paper employed case study, in-depth interview and questionnaire survey as research methods. Seven driving factors of off-site construction had been identified. Four Key Driven Route were developed based on structural equation model (SEM). The results shows that the enterprise to pursue sustainable development is the origin of off-site construction implementation, and government policies are significant factors.