Abstract: RFPA strength finite element software is applied to establish continuous excavation model and once excavation model，and make contrast on the damage mechanism and process of multistage slope under different excavation mode.It is analyzed that local instability effect of multistage slope appears under multiple mining disturbance，by analyzing the local rock mass damage，destruction，instability during the multiple mining activities，and combining with the field monitoring data of quartz stone mine in Jinchuan open pit.In the process of the strength reduction，the continuous mining is introduced to realize the real strength reduction and mining effect，which makes the numerical simulation of the failure mechanism and process more close to the actual damage process.It is mainly shown that：the once excavation and continuous excavation are only different at the time，space position，and the stability analysis of multi-stage slope structure.Their damage process and mechanism basically keep consistent.Under the influence of the time and space effect，the continuous mining of multistage slope mainly show as the local instability and failure.

Key words: Slope stability, Continuous excavation, Once excavation, Damage mechanism, Damage process