Large early autogenous shrinkage and high cracking risk are important problems that limit the popularization and application of alkali-activated slag (AAS) cementitious materials. The use of superabsorbent polymer (SAP) for internal curing is one of the effective methods to solve these problems, but this method will reduce the mechanical properties of AAS. In this study, porous active rice husk ash (RHA) and SAP were combined to form a composite internal curing component (SAP-RHA, SR). The effects of SR and SAP internal curing on the working performance, shrinkage characteristics, hydration products and mechanical properties of AAS were compared and analyzed. The results show that compared with SAP internal curing alone, SR internal curing not only further reduces the autogenous shrinkage of AAS, but also effectively improves its compressive strength, which solves the problem of mechanical properties reduction caused by SAP internal curing to a certain extent.