Understanding the influence of alkali-resistant superabsorbent polymers (SAPs) on the performance of cementitious materials based on Portland Cement (PC) is crucial for optimizing their applications in construction. This study primarily focuses on the effects of varying SAP content on the multiple properties and hydration process of PC materials. The optimal dosage of alkali-resistant SAP (with an absorption capacity of 21.63 g/g in cement) for Portland cement with an effective water-to-cement ratio (w/c) = 0.20 is 0.20 m%. Under the condition of maintaining the same fluidity as the control group, strength decreased by only 2.1 %, autogenous shrinkage was reduced by 36.7 %, hydration of the cement-based material was enhanced, and the porosity of the matrix was reduced. As the SAP dosage increased (from 0.35 m% to 0.80 m%), the degree of cement hydration increased and autogenous shrinkage further decreased, but excessive SAP content led to an increase in residual pores within the matrix, reducing porosity and resulting in lower strength. Although SAP compensates for the negative effects on pore structure in the early stages of hydration, residual effects still contribute to reduced material strength. The study's findings reveal the interaction between SAP content and cementitious material performance, aiming to guide future optimization of SAP incorporation for enhanced material properties and sustainable construction practices.