The application of auxiliary fans without ventilation wall is a very effective and flexible approach to adjust the air flow rates in a mine ventilation network.In this paper,by using the aerodynamic theory for mine ventilation,an analysis is made on airflow process of total pressure ventilation and overcoming ventilation resistance in laneway by auxiliary fan without ventilation wall.It is pointed out that fully using the dynamic pressure with correct direction is very important in order to change all speed energy into dynamic pressure of ventilation.Also,some key technical issues are suggested for the application of dynamic pressure ventilation by auxiliary fan without ventilation wall in mine.