The invention discloses a train traction-brake controller system of urban rail transit and a working method of the system. The system comprises a data input module, a train operation simulation module and a communication interface module; the data input module provides initial parameters for the controller system, and operates the initial parameters; according to the initial parameters, the train operation simulation module obtains traction-brake force information of a train, line information and train attributes, carries out dynamics operation to determine the acceleration and speed of the train at present, and implements a fault simulated calculation on the train; and the communication interface module receives an ATO/ATP control instruction, sends train speed and position information, calculated by the train operation simulation module, to an ATO/ATP, and communicates with a motor to control operation of the motor. According to the route and train information, the traction-brake operation state of the train is simulated, and the working system serves as a test system for the train ATO/ATP to verify the accuracy and reliability of the train ATO/ATP.