With the stability of a counter-tilt slope under bias chasm in mind, based on the rock mass structure cybernetics and combined with the west open-pit mine project of Ping Zhuang, this paper analyzes the failure mode and the landslide mechanism of the counter-tilt slope under bias chasm, using AutoCAD, ANSYS and 3Dslope to model the three-dimensional slope and calculate the slope stability coefficient. The calculation results show that: the three-dimensional landslide modes of the chasm affected zone are: the wedge sliding along the fault plane, the side interface and the weak interface, thus the most dangerous space form of the three-dimensional sliding body is identified; from the stability coefficient under different side interface locations, the influence of the oblique chasm on the slope is revealed. According to the results of the stability analysis, the control scheme of the mining plan is proposed to provide a technical guidance for the open pit mine production safety.