The sharp loss-in-capacity in CO2 capture as a result of sintering is a major drawback for CaO-based sorbents used in the calcium looping process. The decoration of inert supports effectively stabilizes the cyclic CO2 capture performance of CaO-based sorbents via sintering mitigation. A range of Al-decorated and Al/Mg co-decorated CaO-based sorbents were synthesized via an easily scaled-up spray-drying route. The decoration of Al-based and Al/Mg-based supports efficiently enhanced the cyclic CO2 capture capability of CaO-based sorbents under severe testing conditions. The CO2 capture capacity losses of Al-decorated and Al/Mg co-decorated CaO-based sorbents were alleviated, representing more stable CO2 capture performance. The stabilized CO2 capture performance is mainly attributed to the formation of Ca12Al14O33, MgAl2O4, and MgO that act as the skeleton structures to mitigate the sintering of CaCO3 during carbonation/calcination cycles.