Recently study of eco-friendly cars has been carried out actively. Meanwhile, the established mechanism have been replaced by Eco-friendly and efficiency electric motor. Thereof, low saliency surface mounted permanent synchronous motor is selected for Electric Power Steering System(EPS) to acquire the higher steering feeling. Such these driver system are battery-powered that will lead to the DC-link voltage varied according to load current variation and regenerated status. In general, the Torque-Speed mapping is employed without taking into account the DC-link voltage variation in torque control system. Consequently, the additional mapping is indispensable for the high performance estimation of DC-link voltage variation and that is make the system more complicant and responsiveness more slowly. A new torque control system is proposed aim at these drawback with a Flux-Torque mapping to address the issues due to the variations of voltage and speed in practical application in this paper. The proposal current map performance is verified that is capable of dealing the DC-link voltage variation in the MATLAB/SIMULINK and a 500W SPMSM is used to test the feasibility of proposed strategy by a 1kW inverter equipped with Microprocessor Aurix Tricore TC 264D (Infienon.co.)