Periodontitis can lead to defects in the alveolar bone, thus increasing the demand for dependable biomaterials to repair these defects. This study aims to examine the pro-osteogenic and anti-bacterial properties of UPPE/beta-TCP/TTC composites (composed of unsaturated polyphosphoester [UPPE], beta-tricalcium phosphate [beta-TCP], and tetracycline [TTC]) under an inflammatory condition. The morphology of MC3T3-E1 cells on the composite was examined using scanning electron microscopy. The toxicity of the composite to MC3T3-E1 cells was assessed using the Alamar-blue assay. The pro-osteogenic potential of the composite was assessed through ALP staining, ARS staining, RT-PCR, and WB. The antimicrobial properties of the composite were assessed using the zone inhibition assay. The results suggest that: (1) MC3T3-E1 cells exhibited stable adhesion to the surfaces of all four composite groups; (2) the UPPE/beta-TCP/TTC composite demonstrated significantly lower toxicity to MC3T3-E1 cells; and (3) the UPPE/beta-TCP/TTC composite had the most pronounced pro-osteogenic effect on MC3T3-E1 cells by activating the WNT/beta-catenin pathway and displaying superior antibacterial properties. UPPE/beta-TCP/TTC, as a biocomposite, has been shown to possess antibacterial properties and exhibit excellent potential in facilitating osteogenic differentiation of MC3T3-E1 cells.