PEEK has been gradually proposed for the manufacture of artificial joint prostheses in recent years due to its advantages such as good wear resistance, corrosion resistance, and biocompatibility. To study the effect of PEEK instead of CoCrMo as the head of the hip joint on the fretting corrosion resistance, fretting corrosion experiments were performed on PEEK-Ti6Al4V and CoCrMo-Ti6Al4V to simulate the fretting corrosion characteristics of PEEK hip joint prosthesis and CoCrMo hip joint prosthesis in the taper connection. The results show that PEEK-Ti6Al4V had a significantly lower fretting corrosion current than CoCrMo-Ti6Al4V, which indicates that the PEEK hip prosthesis had a significantly lower fretting corrosion rate than the CoCrMo hip prosthesis. However, the corrosion potential of PEEK-Ti6Al4V was significantly higher than that of CoCrMo-Ti6Al4V, which indicates that PEEK hip prosthesis has stronger corrosion resistance. CoCrMo-Ti6Al4V released more types and quantities of metal ions in the lubricating medium, and the total metal ion release is 4.19 times that of PEEK-Ti6Al4V.