In this paper, PID parameters are first normalized on the basis of engineering adjustment, and then are adjusted by fuzzy control principle and fuzzy inference. A fuzzy self-adjustment PID control algorithm is proposed. The PID Controller has the ability of adapting to such complexity and hard control object as non-lined time-varient uncertainly and on. In the end, this algorithm is applied in simulation research of using over-hot system in a power plant as the object. The result shows the algorithm is of reliability and strong ability of anti-disturbance and robustness.