With the depletion of energy, the increasingly prominent problem of environmental pollution and the proposal of carbon peaking and carbon neutrality goals, photovoltaic (hereinafter referred to as “PV”) power generation technology has become a hot spot for many countries to develop, and PV power plants can make a significant contribution to the development of a sustainable energy system. However, PV modules pollution have become a serious problem for PV power plants, which have a great influence on power generation and operating costs. Air pollution, rainfall, module dust accumulation, and ground conditions are key factors that affect the performance and output power of PV modules. This article provides an overview of recent research on the impact of module contamination on PV systems. The study found that the PV power loss caused by component pollution in some power plants reached 5%–20%. This paper aims to analyze the source of module pollution and evaluate the research status of its influence on power generation, so as to provide guidance for the design, operation, and maintenance of PV power plants.