Abstract: The classification and damage mechanism of high and steep slopes in the process of open pit mining are studied.With the monitoring and early warning project of Jinchuan group open pit quartz mine as research background，Matlab software is used to analyze the displacement monitoring data.Combining with the displacement field of slope and the slope failure mode，slope failure is classified into the sliding，the tension，the erosion and the compound.Among them，the sliding and the erosion have characteristics of rapid development and heavily destruction.The tension has slow development and small destruction.The internal mechanism of the slope failure mode is further studied，and the treating measures are put forward according to the slope failure mode.

Key words: Displacement field, Destruction pattern, Destruction of classification, Destruction mechanism, Destruction process