Abstract: Based on the complex mined-out area group of gold deposit in Hebei，the three dimensional calculation model is built with FLAC3D，and used to study the stability of mine open-pit slope under the influence of complex mined-out area group，and the safety factors of slope stability in typical sections have been calculated The results show that the mined-out area group has little impact on the overall stability of slope However，the mined-out area near the slope may cause local instability The slope safety factor is advanced significantly when it has been filled with waste，and the stability is improved obviously This research method can be as a reference for similar mines.

Key words: Complex mined-out area group, Open-pit slope, Stability, Numerical simulation