Against the backdrop of advancing national low-altitude economy strategies, this research examines the factors and mechanisms influencing user acceptance of two differentiated low-altitude air travel services: the fixed-route shuttle (public service type) and 'Feidi' (market-oriented service type). By refining the integrated Technology Acceptance Model–Theory of Planned Behavior (TAM–TPB) framework, a multidimensional "technology-institution-cognition" analytical framework was constructed and empirically validated using a dual-scenario structural equation modeling approach based on questionnaire survey data. The findings reveal that fixed-route shuttle services exhibit a technology-function-dominated decision-making logic, where technology trust not only directly drives usage intention but also indirectly enhances acceptance by improving perceived usefulness and reducing risk perception. In contrast, 'Feidi' services follow an experience-driven decision-making pathway, where technology trust indirectly influences usage intention through attitude, with user decisions relying more heavily on perceived behavioral control and subjective experience. Drawing from the underlying user decision mechanisms, differentiated strategic guidance is provided for manufacturers' technology development priorities, operators' user experience optimization, and regulatory authorities' institutional design, thereby offering theoretical foundation and operational direction for promoting the industrial application of low-altitude air travel services.