Taking coordinated control measures is widely considered as a way to reduce multiple emissions simultaneously. In China, the chlor-alkali/polyvinyl chloride sector is facing great pressure to mitigate air emissions including greenhouse gases. This work presents a set of assessment methods to assess the co-control effects of optional reduction measures on SO2, NOx, and CO2 emissions systematically. These methods include co-control effect coordination system, pollutant reduction cross-elasticity, and unit pollutant abatement cost. A marginal abatement cost curve of single pollutant is constructed to determine technological alternatives that can reduce emission. Results of co-control effect coordination system and pollutant reduction cross-elasticity show that most renewable energy sources, process retrofitting, chemical recovery, as well as energy system optimization measures have good co-control effect. Unit pollutant abatement cost analysis further showed that process retrofitting, chemical recovery, as well as energy-saving measures are superior to renewable energy sources and end-of-pipe measures. Reduction potential analysis of measures is presented using marginal abatement cost curves. The cumulative emission reductions of SO2, NOx, and CO2 are 87,926.0 tons/yr, 49,998.4 tons/yr, and 11.9 × 106 tons/yr, respectively.