The image tailing generated by an Extreme Ultraviolet imager was analyzed and how to remove the image tailing phenomena was proposed. The effects of each component change of coordinate calculation formula on the image were analyzed, and it shows that the superposed signal and Micro Channel Plates (MCP) feedback are the most influential factors of coordinate components in the system. After image data analysis, both cases of superposition of signal, peak accumulation and tail accumulation, were excluded. The calculation on change of quantity of charge at the most serious tailing place shows that the MCP feedback may be the reason of image tailing. However, the amplitude of high voltage applying on the MCP is one of the important factors affecting feedback occurs. The images sampled at 2 950 V and 2 800 V were validated and it indicates that the tailing is sparked by the MCP feedback. Moreover, solutions were given, that are to reduce rudimental gas in the MCP by baking and to clean the MCP by electron beams regularly.