Abstract: Microbial contamination threatens seriously the safety of aviation fuel systems. It can plug fuel pumps and lead to failure of fuel systems of engines, and even ground all planes in the airport. In this paper, domestic and foreign researches on microbial contamination in aviation fuel systems were investigated, and the growth and reproduction environments and conditions of microbes in aviation fuel systems were analyzed. Then, the hazards of microbial contamination to aviation fuel were illustrated from three aspects, i.e., its effect on fuel quality index, interference on normal operation of equipments, electrochemical corrosion on metals. Finally, the methods for detecting microbial contamination of aviation fuel were summarized, and the measures for controlling microbial contamination were specifically proposed. It can be used as the reference for the safety maintenance of aviation fuel systems.