The rock pile develop at the entrance of Daqianshiling tunnel with thick overburden and slope appearance of stable state, but it is easy to be unstable by artificial function of construction work and the disturbance of external environment (such as rainfall and blasting). Based on the development characteristics of rock pile, this paper analyzes the instability mechanism of rock pile at the tunnel entrance, and the stability evaluation of rock pile under static status and construction conditions at the tunnel entrance are detailed both in qualitative and quantitative views, and analyzes the damages to the subgrade, tunnel and some other engineering with treatment methods to ensure the safety of tunnel construction and line operation, which provides reference for the prevention and control of geological disasters caused by rock pile.