Abstract: China’s agricultural green development has entered a new stage of coordinated advancement in “carbon reduction, pollution reduction, green expansion, and growth”. The synergy of pollution reduction and carbon reduction has become an inherent requirement for promoting the green transformation of agriculture. This study empirically examines the synergy of pollution reduction and carbon reduction in China’s planting industry from the perspective of marginal abatement costs. Results show that: 1) The marginal abatement costs for pollution and carbon in China’s planting industry both show a fluctuating upward trend, and the joint abatement strategy is more effective in controlling the costs of pollution reduction and carbon reduction. 2) The synergy of pollution reduction and carbon reduction in China’s planting industry from 2000 to 2022 shows a fluctuating upward trend. The joint abatement strategy is more significant for pollution reduction, while the carbon reduction effect gradually strengthens over time. 3) The synergy of pollution reduction and carbon reduction is highest in the eastern region, followed by the western region, with the central and northeastern regions being relatively lower. There are also significant differences in the synergy of pollution reduction and carbon reduction among provinces. And 4) under four scenarios of ecological protection, carbon reduction priority, energy transition, and agricultural modernization, the synergy of pollution reduction and carbon reduction in the planting industry has a potential improvement space of 37.35% to 39.97%. Based on the above findings, this paper proposes optimal paths for different provinces to achieve synergy in pollution reduction and carbon reduction from the perspectives of minimizing marginal costs and maximizing synergy effects, providing a reference for policy formulation to promote the synergy of pollution reduction and carbon reduction during the “14th Five-Year Plan” period.