A kind of product-troth-flowing fuzzy control algorithm is presented in this paper. The algorithm holds advantage that fuzzy reasoning process is intuitionistic and its computation is simple. Second, based on the algorithm, a constant-ternperature control system is designed with MAX7651, Pt100, MOC3041. Finally, Practical control result shows that the performance of control system is excellent, its rise-time is about 21 minutes, the overshot of temperature is only 0.4℃, and real-time temperature ...