Land use transition pathways have different ecological effects, but the impacts of key conversion processes on habitat quality remain insufficiently understood. Habitat quality was defined as a unitless 0–1 InVEST index of the landscape’s relative capacity to support biodiversity, derived from land-cover suitability and exposure to anthropogenic threats. This study identified key transition pathways affecting habitat quality in the Huaihe River Eco-Economic Belt. Land use data from 2003 to 2023 were analyzed using a coupled PLUS–InVEST framework to simulate land use and habitat quality under four scenarios for 2033, while contribution analysis quantified pathway effects. Cropland continuously decreased, whereas the aggregated impervious-surface category, comprising built structures and paved or artificially sealed surfaces, expanded. Mean habitat quality increased from 0.588 to 0.628, a modest absolute increase of 0.040 on the 0–1 scale, and was higher in the south than in the north. A small number of pathways dominated habitat-quality change; cropland and forest conversion to impervious surfaces were the principal negative pathways. Scenario differences were modest, indicating potential trade-offs among agricultural production, ecosystem conservation, and habitat quality; at the transition-pathway level, the Ecological Protection and Sustainable Development scenarios reduced the negative habitat-quality contributions of specific high-risk conversions, particularly cropland-to-impervious-surface conversion.