Abstract: Based on comprehensive analysis of factors that affect reliability of mine ventilation system, a reliability evaluation index system of coal mine ventilation system was established with 13 main factors as evaluation indexes. Principal component analysis was used to reduce 13 evaluation indexes to 4 comprehensive indexes while getting weight of each comprehensive index according to contribution ratio. Grey relational analysis was adopted to construct reliability evaluation model of coal mine ventilation system, so as to get reliability value of each mine ventilation system. The practicability of the reliability evaluation method of mine ventilation based on principal component analysis and grey relational analysis was verified by an example.