Abstract: Cross-boundary challenges in people's livelihood appeals have become a key constraint on the effectiveness of grassroots governance.Exploring the regularized mechanism for collaborative actions to address the "three-cross" problems(cross-administrative,cross-departmental,cross-domain) within sub-district and town jurisdictions helps enrich research on cross-boundary governance.The core of agile governance for cross-boundary issues lies in integrating governance mechanisms without disrupting the existing grassroots administrative operation system,and leveraging administrative resources to resolve "three-cross" problems within governance boundaries through a "dimension elevation and reduction" approach.Different from the Western agile governance proposition of "de-bureaucratization",the "integrated multi-grid" mechanism—relying on Party building leadership and administrative empowerment—is more aligned with the construction of China's localized independent knowledge system.Against a broader institutional backdrop,exploring the interaction and structural symbiosis between factors such as agile governance structure,governance process,and governance tools holds significant practical value and theoretical significance for grassroots governance in megacities.