Carbide slag (CS) is a CaO-based waste with superior CO2 capture capacity. As it is usually recycled in the form of fine powder, the pelletization of CS is indispensable for its practical application. Here, commercial Portland cement (PC) was used as a cheap binder to produce PC-based carbide slag (PCCS) pellets and to enhance the mechanical strength of CS. The carbonation conversion of CS declined with the addition of PC, but the ability to resist sintering was improved. Prolonging the hydration time (HT) was effective in improving the CO2 capture performance of PCCS. During the thermal pretreatment of CS, the grain size of the CS increased with increasing thermal pretreatment temperature and time, but the mechanical strength of the CS increased.