Regional governance is an important meso-level of metropolitan area management, and optimizing regional cooperation mechanisms is essential to the modernization of national governance. In order to clarify the difficulties and opportunities for improvement in the current collaboration mechanism, this paper discusses the participants and demands of institutional collective action in the Beijing-Tianjin-Hebei regional collaboration, analyzes the issues of concern and action costs of Beijing, Tianjin and Hebei governments, as well as the ways in which different levels of official institutions participate in regional cooperation, explores the operating mechanism in the practice of Beijing-Tianjin-Hebei regional cooperation, establishes the interaction logic among regional variables, cooperation mechanisms, cooperation risks and costs,and analyzes the main dilemma and solution mechanism of regional collective action. The study points out that the evolution of regional problems is the main source of promoting the improvement of regional governance, the basic variables of regional cooperation come from the actual situation of the region, and its root is the political, social, and economic network formed in the region for a long time, including: the existing system, regional structure and regional problems to be solved, the demands and urgency of actors involved in regional cooperation, and the spontaneous collaboration and interaction network between local organizations; Intermediary variables are process variables derived from basic variables in cooperative actions, including: the field and scope of cooperation, the composition of participants, the motivation of actors, and the degree of intervention of mandatory power; The basic variables and the intermediary variables act together on the regional cooperation mechanism and have an impact on transaction costs and cooperation risks, and ultimately affect the benefits and effectiveness of cooperation. In order to alleviate the dilemma of institutional collective action in regional cooperation more effectively, it is first necessary to comprehensively analyze the problem areas, local cooperation networks and other variables involved in the ICA dilemma in regional cooperation, and select a cooperation mechanism suitable for the nature of the dilemma by balancing the efficiency and cost of cooperation. Secondly, we should actively foster multilateral and bilateral cooperation between government agencies at all levels, promote the formation of a flexible, orderly and self-adaptable negotiation mechanism, ensure the self-interest and autonomy of collective actors, and develop the relationship of mutual benefit and trust, so as to obtain a stable impetus for ICA action. At the same time, it is also necessary to establish a common regional goal system, and try to achieve the overall regional goal through compromise and concession between individuals.