In order to understand the effect of SO2 on the CO2 capture performance under pressurized carbonation conditions, tests by orthogonal design were carried out in a calcination/pressurized carbonation reactor system. The effects of variables such as carbonation temperature, carbonation pressure, SO2 concentration, CO2 concentration, and the number of cycles on carbonation and sulfation were investigated. A range method was employed for analysis. Phase structure and scanning electron microscopy images were measured as supplement for a reaction study. Temperature increase enhanced the SO2 capture, leading to a rapid decay in CO2 uptake. The carbonation pressure had a stronger effect on the CO2 uptake than the temperature. SO2 uptake increased rapidly with increasing pressure while CO2 uptake decreased.