Abstract: The transportation sector contributes approximately 20% of global carbon emissions, with road vehicles accounting for as high as 80% of this proportion. To advance the low-carbon transition in the transportation field, this study, based on a life cycle assessment framework, systematically compares and analyzes the carbon emission characteristics of fuel vehicles, battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), and fuel cell vehicles (FCVs) across the three stages of production, use, and end-of-life over the past decade, and proposes targeted carbon reduction strategies. The results reveal significant stage-specific differences in carbon emissions: the production stage contributes 25%-50% of life cycle emissions, with BEVs and FCVs accounting for the highest proportion due to the manufacturing of power batteries and fuel cells; the use stage makes up 50%-70%, where the carbon emission intensity of traditional fuel vehicles far exceeds that of BEVs and FCVs; the end-of-life stage accounts for 7%-22%, with battery recycling of new energy vehicles being the main emission source. Notably, carbon emissions are significantly affected by regional and technological dynamics: differences in grid cleanliness lead to a 40% fluctuation in the emission reduction benefits of BEVs; among hydrogen production methods, water electrolysis reduces emissions by over 55% compared to fossil-based hydrogen production. Accordingly, a three-in-one collaborative carbon reduction pathway of "process optimization - energy substitution - technological innovation" is proposed: in the production stage, carbon reduction is achieved through lightweighting, upgrading of welding and painting processes, and green synthesis of batteries; in the use stage, it relies on the promotion of clean power grids and green hydrogen; in the end-of-life stage, hydrometallurgy and cascade utilization are promoted. This study provides a systematic scientific basis for carbon neutrality in the automotive industry.