The invention relates to a four-phase (8/6 pole) switch magnetic resistance motor control device of a single current sensor and a realized method thereof. The invention mainly comprises a current detecting circuit, a power conversion circuit, an A/D conversion circuit, a digital signal processing (DSP) controller circuit and a switch magnetic resistance motor; the power conversion circuit is respectively connected with the current detecting circuit and the switch magnetic resistance circuit; the current detecting circuit is also connected with the A/D conversion circuit; the A/D conversion circuit is connected with the digital signal processing (DSP) controller circuit. The invention has simple structure and convenient detection, and can be applied to switch magnetic resistance motor speedregulation systems such as robots, numerical control machine tools, radar tracking, artillery following, etc. systems, including the industries such as mine, metallurgy, power, chemical engineering,petroleum, etc., which can effectively improve the performance of the system and enhances control precision.