In order to study formation stress influence to mining roadway stability， through the analysis of mining roadway stress field theory， the theory that roadway vertical stress and the horizontal stress can contact through a comprehensive lateral pressure coefficient was put forward， by ANSYS numerical simulation software， roadway under different lateral pressure coefficient of the distribution of effective stress and the change trend of each key point with the lateral pressure coefficient of roadway were simulated， the result showed that when the lateral pressure coefficient is less than 1， the destruction of the roadway is mainly of roof and floor closer， when the lateral pressure coefficient is equal to 1， the destruction of the roadway is mainly smaller sectional area of the overall， when the lateral pressure coefficient is greater than 1， the destruction of the roadway is mainly roadway sides closer， cause roof caving and the floor heave. The key points of effective stress of roadway with the increase of lateral pressure coefficient has a rising trend.