Proton exchange membrane fuel cell(PEMFC) is being paid to special attention around the world duo to their zero pollution, low noise, high energy density, high efficiency and fast response, thus it is developing rapidly in recent years. However, the lifespan of PEMFC vehicle is an important issue that restricts its commercialization. Local current density is an important parameter during the operation of PEMFC, which can be used as the fault diagnosis and positioning tool, improving the operation durability and stability of PEMFC. Moreover, the internal information of an operating PEMFC can be also revealed by the local current density, providing comprehensive understanding of the reaction mechanism and guidance for the optimization design of PEMFC. In consequence, it is of great importance for the thorough and comprehensive research of the local current density. In this paper, the methods for the in-situ and real-time measurement of the local current density are introduced and analyzed, and the results obtained by previous experiments and numerical simulation are compared. The effect of operation parameters on local current density have been summarized in detail and the applications of local current density in fuel cell analysis are reviewed. Finally, the development tendency is proposed based on the research progress of this topic.