Traditional control theory has strong control ability for a clear system,but to the system,which is too complex or difficult to accurately describe,it has to do nothing to help.Therefore,we try to use fuzzy mathematics to deal with these control problems.Through the PID control system of the analysis,this article offers a kind of fuzzy control method,the fuzzy controller,which can improve the design of the main steam temperature control system,endow the fuzzy control system with the stronger adaptive ability.As a result,the control time becomes faster,and the robustness is much enhanced.