Abstract: Through the site in situ test , slope weathering fracture zone test, slope structural plane investigation, rock mass quality evaluation, slope rock mass strength parameter analysis, rock mass strength index back analysis and slope stability calculation were done on Miaogou Iron Mine slope, open pit final slope angle of Miaogou Iron Mine could increase from original design 48° to 52° was proposed, and economic effect was analyzed.

Key words: Slope rock mass, Stability, Final slope angle