Abstract: Though the finite element numerical simulation，the method which is used to calculate the slope dynamic safety factor is put forward，combined with monitoring data of blasting ground vibration.Through the dynamic finite element and time-histories analysis，the change characteristics that safety factor declines with the blasting loading increase is obtained.When the safety factor is one，the slope is in the critical state.At this moment，the particle velocity is the critical value，and the slope critical vibration velocity is calculated out by the interpolation method.Combined with the blasting seismic wave propagation law，blasting safety distance is gained inversely，which provides scientific and effective reference for the slope maintenance and production blasting.

Key words: Dynamic loading, Slope stability, Critical vibration velocity, Safety distance, Numerical simulation