The governance of cross-border urban agglomerations is an important part of the governance of urban agglomerations in our country，and is also an important part of the collaborative governance of grassroots governments in adjacent areas. The antecedent conditions，driving factors and the power interaction laws behind the cross-domain inter-governmental cooperative governance practices of the "Tingqiaohe" urban agglomeration are summarized，revealing the generation logic of the grassroots governments cross-domain cooperation system. The complexity of cross-domain problems and the tension of fragmented governance of grassroots governments，the mutual dependence of resources，the cost of cooperation， and vertical intervention have contributed to the generation of cooperation willingness， while the vertical superior pressure and horizontal coordination and linkage drive the operation of cooperation，and finally achieve the result of mutual trust and improved benefit levels. The induced change of macro-concepts，the incentive constraints of meso-systems，and the effective coordination of micro-actions are the inherent logic of “gradual consensus-based” cooperation. In the future，in cross-domain cooperative governance，the guiding role of superior administrative authority should be fully utilized，and the innovation of inter-governmental cooperation system should be promoted according to the nature of cross-domain public issues，transaction costs and other factors，and social forces should be actively introduced to participate in the cooperation，so as to avoid the occurrence of problems such as delayed action.