The carbon emission optimization goal is easy to achieve local optima, which affects the optimization effect. Therefore, a multi-objective optimization method for manufacturing carbon emissions based on the firefly algorithm was designed. On the basis of the Firefly algorithm, a multi-objective optimization model for carbon emissions in the manufacturing industry was constructed, enabling other goals to achieve global optimization, fully considering the changes in energy structure, energy intensity, and economic changes, and achieving the carbon emission reduction task of the manufacturing industry. The comparative experimental results show that this method has good carbon emission optimization effect and can be applied in practical life.