governance system. Existing research has found that policy attributes, hierarchies and institutional environments are important factors leading to different modes of policy implementation. This paper integrates the two key variables of institutional coupling and situational incentive to construct a theoretical analysis framework, and then divides the policy implementation modes into four execution modes of competitive innovation, administrative utilization, symbolic leadership, and conflict adjustment, in order to open the process "black box" of the different policy implementation modes.  Through the multi-case comparative study of different party and government departments, townships and streets in L City which is to general establish legal counsel system, the theoretical presupposition is verified in this paper. At the same time, this paper finds that as the "sinking" of superior policies impacts the governance field of local governments, the two key influencing factors, institutional coupling and situational incentive, shape the response process and behavior pattern of stripe department and block department within local governments, through the dynamic mechanism of legitimacy recognition and political-economic incentive under the dual logic of legitimacy and rationality. The typification of different policy implementation modes not only expands the research related to the differentiated models of policy implementation, but also expands the research related to the organizational behavioral logic.