In this paper, PID Parameters are first normalized on the basis of engineering adjustment, and then are adjusted by Fuzzy control principle and fuzzy interence. A fuzzy self-adjustment PID controll 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 reasearch of using over-hot system in a power plant as the object. The result shows the algorithm is of reliability and strong ablility of anti-disturbance and robustness.