Zirconia and ultra-high molecular weight polyethylene (UHMWPE) are common materials for artificial joints. However, the failure of artificial joints is mainly caused by the wear of UHMWPE. Therefore, the development of effective measures to enhance the service life of UHMWPE is one of the most important facets of research on total joint replacement. The purpose of this study is to use an atmospheric-pressure plasma system to modify zirconia and UHMPWE surfaces, which is expected to increase the adsorption of joint-lubricating fluids, thus reducing the abrasion and wear of UHMWPE (73% improvement). Surface modification experiments were carried out using an atmospheric-pressure plasma system, while fourier transform infrared spectroscopy was used to characterize the surfaces treated with atmospheric-pressure plasma. The results of water contact angle tests indicated that the plasma-treated material surfaces exhibited excellent hydrophilicity (70% improvement). In addition, the treatment of materials with atmospheric plasma was confirmed to increase the adsorption of lubricating fluid and reduce wear, thus extending the service life of UHMWPE.