To address the dual challenges posed by the growth of urban transportation demand and the carbon neutrality goal, it is crucial to explore in-depth emission reduction paths in the transportation sector. Taking Beijing as an example, this paper focuses on the “key technologies for online car-hailing integrated travel guidance services and low-carbon development”, aiming to construct an innovative system that drives the online car-hailing industry towards green and low-carbon transformation. The overall scale, operation characteristics, and new-energy development trends of the online car-hailing market in Beijing are systematically analyzed, and a carbon emission accounting model is constructed. On this basis, this paper focuses on developing a data-driven low-carbon travel guidance service mechanism centered on “carbon inclusion.” This mechanism quantifies the baseline emissions and project-scenario emissions. It accurately calculates and rewards the carbon emission reduction of passengers’ active choice of new-energy online car-hailing, forming a technical closed-loop of “data monitoring-emission reduction accounting-value incentive-behavior guidance.” The research results provide low-carbon development solutions with both technical feasibility and application value for urban transportation managers and travel platforms, and have important demonstration significance for promoting the achievement of the “dual carbon” goal in the transportation sector.