Parallel groove clamps are one of the key components ensuring the safe operation of power systems. The contact performance of the parallel groove clamp is a critical issue in power system research. This study first introduces the specific definition and classification of fretting wear, along with Archard’s wear law. A finite element simulation model of fretting wear in a parallel groove clamp is then established, where load and displacement conditions are applied. The simulation reveals that global slip leads to a U-shaped wear profile, while local slip results in a W-shaped profile. Based on the simulation results, it is found that in the early stage of fretting wear, the actual contact area increases due to material removal. Under this condition, the contact resistance of the parallel groove clamp tends to decrease as the contact area increases. By adopting a decoupled simulation strategy, this study effectively addresses the convergence challenges typically associated with nonlinear electrical-mechanical coupling in fretting wear analysis.