The residual thrust method (RTM), which is widely used in slope stability analysis, assumes the interslice force direction is parallel to the slip surface of the upper slice. This assumption is intuitive and reasonable. With the force equilibrium equations, stability factor can be solved. The paper puts forward the improved residual trust method. The interslice force direction is modified by multiplying the same correction coefficient. Then the correction coefficient, which is named as thrust direction correction coefficient, is solved in consideration of moment equilibrium. The improved residual thrust method can reveal the possible changes of interslice force direction under different calculation conditions, may improve the reliability of calculation. At last, the improved residual thrust method is applied in practical engineering and the results are discussed.