The analysis of stepping motor’s model were different due to it’s applied situation. For controlling the load with large moment of inertia to fulfill rapid startuping and stopping procedure, the topic created an analying method of open-loop single-step control of stepping motor through starting with the model of stepping motor, predigesting Leenhouts circuit model, importing the driver circuit model and dynamics equation. Also, topic instantiated the model via Mathcad tool, analysed and calculated the time parameter of the open-loop single-time controlling under the certain situation, listed the curves of the electromagnetic torque, angle acceleration, angle speed and mechanical angle.