Hydrogels possess inherent characteristics that render them promising for the prevention of peri-implantitis. Nonetheless, hydrogels with singular network structures are incapable of concurrently achieving the desired adhesion and mechanical properties. In this work, a carboxymethyl resistant starch/polyacrylic acid semi-interpenetrating (CMRS/PAA semi-IPN) hydrogel was successfully prepared in one step. Its morphology, structure, mechanical properties, and adhesion properties were systematically assessed, which revealed a homogeneously porous structure with a commendable mechanical strength of 67.317 kPa and an adhesion strength of 63 kPa. Ciprofloxacin (Cip) was loaded in the CMRS/PAA hydrogel via in situ compounding. The in vitro kinetic study of drug release shows that the slow drug release efficiency exceeds 90 % in the weakly acidic microenvironment at the infection site after 72 h, indicating enhanced antimicrobial properties. The Cip-loaded hydrogel also exhibits a remarkable bacterial inhibition rate exceeding 99 % against the pathogenic bacterium P. gingivalis and good cytocompatibility and hemocompatibility in vitro. In summary, the current work explored a novel solution and direction for the development of anti-infective medical materials applicable to dental implants.