Abstract: The cause analysis of air lock for the automobiles used in plateau is carried out. It is pointed out that the main factors of the air lock produced are induced by natural environment, products quality, the structure of fuel supply system and human factor. The suggestions to eliminate the air lock are given, including changing the installation way of gasoline filter, adjusting the performance parameter, enhancing the heat isolation and diffusion ability of fuel supply and exhaust system, optimizing the design of fueling system, adopting crystal pump, coating the fueling system with macromolecular material and using quality fraction gasoline.