Abstract: Thermal power plant thermal control system is the core technical mode to ensure the safe, stable and economic operation of large-scale generator sets, with key functions such as parameter monitoring, closed-loop regulation, logic control and safety protection. With the continuous development of units towards large capacity, high parameters and intelligence, the thermal control system is facing a series of prominent problems, such as insufficient measurement accuracy, poor adaptability of control algorithms, unstable operation of DCS system, slow response of actuators and imperfect protection logic, which directly affect the regulation quality and operation safety of units. Based on the theories of thermal automatic control, distributed control and intelligent regulation, this paper systematically sorts out the typical faults and weak links in the current operation, and puts forward targeted improvement measures from five dimensions: measurement system optimization, control algorithm upgrading, DCS architecture improvement, actuator management and protection system strengthening. These measures can effectively improve control accuracy, enhance system anti-interference ability, shorten regulation time and reduce overshoot, so as to realize the stable and reliable operation of the whole process of thermal control system. The research results can provide theoretical reference and engineering practice basis for the transformation, operation and maintenance optimization and intelligent upgrading of thermal power plant thermal control systems.