Urban heritage, as a carrier of a city’s history, spirit, culture, and collective memory, is increasingly valued. Establishing urban heritage trails enables the threading of heritage sites together, integrating them more broadly into people’s lives. The primary task in creating urban heritage trails lies in selecting optimal routes. As theories of urban heritage conservation evolve, the concept of the Historic Urban LandscapeHistoric Urban Landscape (HUL) (HUL) has gained wider acceptance. This theory posits that urban heritage exhibits historical layeringHistorical layering, which visually manifests the imprints of a city’s development and evolution across different historical periods. This study adopts the HULHistoric Urban Landscape (HUL) perspective to systematically review the historical layeringHistorical layering of the Macau Peninsula, examining the characteristics and shifting focal points of urban development throughout its history. Subsequently, an evaluation system for the layering richness of urban cultural heritage trailsUrban cultural heritage trail is developed based on the concept of heritage layering. This framework is applied to analyze and assess existing routes within the core zone of the Historic Centre of MacauHistoric Centre of Macau. Relevant tools are then applied to optimize these routes based on evaluation results. Finally, the optimized outcomes are compared and validated. The results indicate a measurable improvement in layering richness following optimization. Using the Macau Peninsula as a case study, this research explores an evaluation system and optimization methodology for heritage trails based on layering richness. It aims to provide innovative insights for route selection in themed heritage trail development while enhancing public understanding of urban heritage layering and strengthening awareness of heritage conservation.