The utility model discloses a control system fault detection system of thermal power plant based on data driven calculates through carry out PLS to the non -linear control signal of thermal power plant, realizes real time monitoring and detection to the system failure. This system includes: the sensor is arranged near the control system's of thermal power plant executor, including temperature sensor, pressure sensor and the flow sensor of at least one, storage module carries out wired or wireless connection with the sensor for the signal of storage sensor, PLS processing module is with storagemodule electrical connection for the PLS model is set up to receiving sensor's signal, and carries out the PLS operation based on the PLS model to the signal of sensor, the alarm is with PLS processing module electrical connection for receive PLS processing module's PLS computation result, and send alarm signal.