Abstract: Fuzzy PID controller, which can control common rail fuel pressure accurately, is designed in order to realize dynamic regulation of fuel pressure to break the limitations of traditional PID controls. Self correction demand of parameters is acquired after an analysis of the response of system output. Problem domain of the input and output language variables is ascertained depending on the results of computation in the singlechip. Control regulation of the fuzzy controller and fuzzy control table of parameters are given. The controller can be realized on a singlechip. Experimental results show that it functions well.