The synergy of pollution control and carbon reduction is conducive to promoting the green transformation of the economy. Based on China’s 30 provincial administrative panel data from 2002 to 2020, using the elastic concept to measure the synergy index and the panel fixed effect model to carry out empirical analysis, we analyzed the relation between environmental regulation and the synergy of pollution control and carbon reduction. The results revealed that: (1) Environmental regulation positively influenced the synergy of pollution control and carbon reduction in hog breeding. (2) Different types of pollution and carbon reduction had different synergistic effects. Compared with chemical oxygen demand and ammonia nitrogen, the positive effect of environmental regulation on the synergy of total phosphorus and carbon reduction was relatively weaker. (3) From the perspective of impact mechanisms, environmental regulation mainly achieved synergies through the “production constraint effect” and the “innovation compensation effect”. (4) Further analysis showed that environmental regulation had a significant scale threshold effect on the synergy of pollution control and carbon reduction in hog breeding. Therefore, the heterogeneity of pollutants and industrial scale should be considered in the optimization of environmental regulation policies.