Abstract: Based on the proposed arbitrary three-dimensional sliding surface search, for the sliding body of asymmetry (including the case of asymmetry of standard line and asymmetry of length), mother line being not in the largest cross-section of the sliding body along the sliding direction and slopes with weak interlayer, some solution measures are used. Then they are applied to four examples in the engineering: common excavation and filling compound slope, filling embankment at form of hierarchical level, vertical section of road with flat and oblique slope and the slope with weak interlayer. Analysis shows that: firstly, this method can be employed to analyze stability of some slopes under complex conditions and to find the optimization of the most dangerous sliding surface (including the general and partial stability); secondly, when the fill and excavation materials are inconsistent in excavation and filling compound slope, the sliding instability occurs more easily at poor stability of materials, but in the case of filling and excavation materials with the same severe γ, whether or not φ / c of the two materials is equal impacts symmetry and size of the sliding body on a certain extent; thirdly, for the slope of vertical section of road with flat slope, the most dangerous sliding surface is more inclined to flat slope section of the slope, and oblique slope section of the slope has some positive impact on the slope stability; fourthly, in the slope with weak interlayer, when the length of sliding body reaches infinite length, its three-dimensional stability tends to two-dimensional stability, and the results from this method are very close when compared with the previous results of other methods, so it shows that this method is feasible.