The traditional mine accumulator locomotive usually takes the DC motor for its power source. And the series-wound resistance method is usually used in its speed control. With the development of power electronics technology, the AC drive system based on power electronic converters can be realized. Especially after the realization of large-scale integration and compmer controling, the performance of AC variale speed has been improved a lot. In operation, the mine accumulator locomotive not only works in frequent starting, breaking, accelerating and decelerating conditions, but also has to adapt to the bad pavement. The AC asynchronous motor has simple stmcture, sturdy and durable, and it could save power by notusing resistance when it was used in speed control. With this characteristics, the AC speed control system has the feature of fast response and high overload capacity. The AC speed system is the key factor for efficient operation of mining accumulator locomotive. Compared with the traditional DC speed system, the principle of DTC is introduced in this paper. And the advantage of operating performance and economic benefit of mining accumulator locomotive with AC speed system based on DTC is analyzed from practical application.