Objective Megacities are generally characterized by serious urban scale expansion and dense population, which has resulted in increasingly prominent problems such as insufficient green space and uneven spatial distribution. In order to better solve these problems, at the beginning of 2023, the Ministry of Housing and Urban-Rural Development issued the Notice on the Pilot Work of Opening and Sharing of Urban Parks and Green Spaces, which encourages localities to break new ground in the opening and sharing of parks and green spaces in a pilot manner, so as to meet the new needs and expectations of the people in the new era. Since then, all parts of the country have begun to open and share urban parks and green spaces. However, currently, such opening and sharing in China is still in the stage of free exploration without sufficient theoretical research or practical experience. As a benchmark for other large, medium and small cities, megacities are of great practical significance in exploring new paths for opening and sharing parks and green spaces in a balanced, efficient and scientific way, in order to enhance the multiple service functions of parks and satisfy the people’s aspirations for a better life. Therefore, it is urgent to think about how to realize the long-term development of innovative means and implementation paths for the opening and sharing of parks and green spaces in megacities.

Methods/process  Megacities, as a higher-order form of urban development, have the most excellent allocation of resources for parks and green spaces, while also facing greater construction pressure and severe problems than small cities, such as uneven distribution of green space resources and limitation of park service scope. By sorting out the current implementation of park opening and sharing in megacities and analyzing the deep-rooted internal reasons, which are crucial for promoting the pilot opening and sharing of parks in the future, this research summarizes the following four problems. 1) Green space layout problem: Uneven distribution of green space for the implementation of park opening and sharing in megacities. 2) Green space utilization problem: The open and shared park green spaces in megacities are inefficiently utilized. 3) Green space operation and maintenance problem: The open and shared park operation mode of megacities keeps to the beaten track. 4) Green space management problem: The park management system of megacities is inefficient, random and extensive. In such egacities as Singapore, London, Tokyo and New York , the research and practice of park opening and sharing have been carried out for a relatively long period of time, gradually giving birth to a perfect top-level design approach, an efficient and feasible planning system, a multi-party operation mode, and a scientific and reasonable later-stage management and operation mechanism in the specific implementation of park opening and sharing, which can provide certain inspirations for the opening and sharing of China’s parks. By analyzing the practice of park opening and sharing in the four international megacities in combination with relevant policy and legislation, planning idea, operation system and management mode, the research systematically summarizes the characteristic highlights and successful experience in park opening and sharing of the megacities from the following four aspects, respectively. 1) Inspiration from Singapore’s experience: Strengthen top-level design and insist on government leadership. 2) Inspiration from London’s experience: Prepose grading and classification under the guidance of macro-planning. 3) Inspiration from Tokyo’s experience: Clarify park operators and diversify participants. 4) Inspiration from New York’s experience: Ensure flexible management and maintenance, and rational utilization of resources.

Results/conclusion  This research systematically sorts out the development paths of parks in foreign megacities to realize high-quality opening and sharing, summarizes their characteristic highlights and successful experiences in park renewal and reconstruction, and puts forward the opening and sharing model of parks and green spaces in China’s megacities that is oriented by realistic problems, guaranteed by policies and regulations, guided by macro-planning, and based on fine management, so as to promote the standardization, scientification, and rationalization of the opening and sharing of urban parks and green spaces, and provide certain reference for deepening park opening and sharing in the future. Moreover, the research also provides some reference suggestions for the implementation of park opening and sharing in China from the following four aspects, respectively. 1) Improve the policies and regulations on park opening and sharing, and strengthen the governmental top-level design. 2) Regulate the layout of green space under the guidance of macro-planning, and build a hierarchical classification system following the principle of preposition. 3) Attract social organizations to highly participate in park operation, and establish an efficient multi-party cooperation mechanism. 4) Improve the long-term mechanism of park management, and strengthen the ability of fine management. The park opening and sharing work of China is a concrete implementation and embodiment of the “people-centered” development concept, well responding to the people’s urgent demand for urban green public space. In the future, the opening and sharing of urban parks in China will make steady progress and achieve long-term development.