Focusing on the Shandong Peninsula urban agglomeration, this study examines the spatiotemporal patterns and influencing factors of multilayer hinterland relationships within urban innovation networks from both national and local spatial perspectives. The analysis is based on a multilayer innovation network constructed from intercity patent transfers, scientific co-authorships, and venture capital investments, using data from the years 2010, 2015, 2020, and 2023. Three conclusions are drawn. First, in terms of self-network size, the proportion of weak components and reach efficiency, the Shandong Peninsula urban agglomeration has been increasingly integrated into China's multi-level innovation network, with its network structure gradually evolving towards a polycentric and decentralized pattern. Second, at the local scale, the multilayer hinterland ties are especially strong within the Provincial Capital Economic Circle and between it and the Jiaodong Economic Circle, while the Lunan Economic Circle exhibits relatively weak internal and external connections.At the national scale, multilayer hinterland linkages are primarily concentrated with cities in the BeijingTianjin-Hebei, Yangtze River Delta, and Guangdong-Hong Kong-Macao urban agglomerations. Third, the paired cities' innovation capacity, administrative rank, level of digital economy development, and high-speed rail connectivity have positive effects on multilayer hinterland relationships, while GDP gradients and geographic distance exert negative impacts.