Abstract: Mine ventilation system can be divided into safety sub-regions by analyzing the function and feature of each part in ventilation. This safety sub-region can offer clearer perspective for ventilation analysis and modularization management. In this paper, a ventilation safety sub-region partition method was proposed.Because safety sub-regions boundaries often blurred，based on regional and modular characteristics of ventilation system,six different types of sub-region were built including intake region, return region, air-required region, upstream of air-consume region, downstream of air-consume region, and the other region. Using breadth-first search algorithm, mine ventilation system structure was analyzed. On this foundation, together airflow relation matrix and ventilation safety logic a partition method was given for ventilation decomposition. The validity and rationality of the methods were demonstrated in Huangling No.2 coal mine.