In order to promote the transformation of prefabricated buildings towards low carbon, based on the theory of planned behavior and stakeholder theory， structural equation modeling is used to analyze the role of contractors' internal and external drivers on the contractor's low-carbon management behavior and analyze the enterprise economic effect, social effect and environmental effect produced by the contractor's low-carbon management behavior. The results show that behavioral attitudes, subjective norms, perceived behavioral control, government departments, construction units, design units and PC production and supply units have significant impact on contractors' low-carbon management behavior; the public's influence on its behavior is not significant; among the internal factors of the enterprise, its behavior attitude has the most significant impact on its behavior; for external driving factors of the enterprise, the construction unit has the most significant impact on behavior; the low-carbon management behavior of contractors not only brings economic effects to enterprises, but also brings corresponding social effects and environmental effects. All participants should pay great attention to the driving factors affecting the low-carbon management behavior of contractors to promote the healthy development of prefabricated buildings.