As China enters a new era of high-quality development, the mode of regional development is transforming from traditional administrative division to regional integration strategy. Meanwhile, the construction of cross-regional public service collaborative policies is essential. Although the local government is mainly responsible for the supply of localized public services, the cross-regional public service collaborative policy has the attribute of horizontal intergovernmental cooperation, and the horizontal intergovernmental structure has an important impact on the cross-regional public service collaborative policy behavior. This paper focuses on the influence of special dual-weakened intergovernmental structure (abbreviated as “DWIS”), which referred to a situation of both in weak financial resources and weak policy capacity for nearby two local governments. From the perspective of resource-capability theory, an adaptive bonding analysis framework is constructed based on the three dimensions of goal constraint, motivation induction and discourse construction. Combined with the case study of cross-domain bus between Y city and its adjacent Z new district in the Yangtze River Delta region, an adaptive bonding analysis is carried out on the formation mechanism of the collaborative policy dilemma influenced by the DWIS factors. The result reveals that the DWIS factor has a distorting effect of adaptive bonding mechanisms on the cross-regional public service collaborative policy decision and implementation process. Specifically, the shortage of financial resources weakened the motivation of local government’s participation in collaborative policy, and the lack of policy capabilities reduced the ability for conflict management in the policy process, which resulting in barriers in target integration, motivation induction as well as incompatibility of multi-dimensional discourse systems. Therefore, in order to speed up the process of regional integration, it is necessary to attach importance to the DWIS factor existing in adjacent governments’ cooperation in low development gradient areas, and take multiple measures to solve the dilemma of the government’s participation in cross-regional public service collaborative policy and even in process of regional integration development.