An electrical control system of a numerical control machine tool comprises a control unit, a control instruction generation unit, a display unit, a main shaft frequency conversion system, a servo driving system, a tool changing system and a hydraulic system. The input end of the control unit is connected with the control instruction generation unit, and the output end of the control unit is connected with the display unit, the main shaft frequency conversion system, the servo driving system, the tool changing system and the hydraulic system. A simulation control signal is generated by the control unit according to a simulation instruction, and machine tool machining simulation is performed. The simulation result is sent to the display unit, the simulation result is displayed through the display unit, if the simulation result conforms to a machining drawing, workpiece machining can be started, and if the simulation result does not conform to the machining drawing, the simulation instruction can be returned to be input again, the input simulation instruction is changed and simulated again, and therefore, the use procedure of a user is simplified, the market requirement is met, and wide application prospects are achieved.