In view of the public affairs nature of environmental governance，regional environmental collaborative governance is first and foremost a collaboration between government entities. In order to further effectively promote the coordinated governance of the regional environment in the Yangtze River Delta，it is necessary to improve the structure of regional environmental collaborative governance. Since the start of the integrated development process in the Yangtze River Delta，regional collaborative governance has gone through different stages of development，such as a single-level environmental collaborative governance structure，the multi-level environmental collaborative governance structure with “three-level operation” as its main feature，and a governance structure that has experienced both vertical control and horizontal coordination. At present，the environmental collaborative governance mechanism in the Yangtze River Delta is essentially a collaborative governance mechanism for communication，negotiation，and consultation. The collaborative environmental governance structure and coordination mechanism are generally loose. The Yangtze River Delta environmental collaborative governance structure also faces decision-making bottlenecks，execution bottlenecks and regulatory bottlenecks. As the integration of the Yangtze River Delta develops into a national strategy，the Yangtze River Delta should strengthen the vertical environmental collaborative governance structure，promote market-oriented socialization mechanism innovation，unify regional ecological environmental protection systems，and carry out performance evaluation of environmental collaborative governance，and finally form a new regional environmental collaborative governance structure that combines vertical control with horizontal coordination.