Aiming at the problem of terminal voltage pulse caused by non conducting phase continuum during commutation of brushless DC motor, based on the principle of back electromotive force (EMF) zero crossing, the causes of terminal voltage pulse and its influence on the detection accuracy of back EMF zero crossing were analyzed. A control strategy for high precision commutation of sensorless brushless DC motor by avoiding terminal voltage pulse using software algorithm was proposed. The conditional statement and program run time difference were used to avoid the terminal voltage pulse. At the same time, in order to improve the fault tolerance rate of run time difference of the designed program under heavy load, a strategy to reduce commutation continuum time was proposed. Finally, a sensorless brushless DC motor experimental platform was built to verify the above strategy. The experimental results showed the effectiveness and accuracy of the proposed strategy under different duty cycles and loads.