Abstract: The control strategy of steam temperature control system of the 600MW unit in Harbin Third Power Plant of Huadian Energy Company Limited was introduced. The functions, the principle and the system configuration of the optimized steam temperature control system were expounded; the realization method of communication with INFI-90 system was explained; and the hardware configuration, the control logic and the implementation contents were described. Using the powerful intelligent calculation and control functions of the STOCS system control software package, according to analysis of the working condition variation of the boiler and the heating ability of each superheater, the amount of the attemperating water for keeping the main steam temperature in the set value was calculated exactly，and the target of accurate steam temperature control was realized.

Key words: optimized steam temperature control system, function, feature, principle, configuration, structure of communication system, interface logic, implementation contents