In order to study the stability of unsaturated land slope under rainfall infiltration condition, using the finite element method of the saturated-unsaturated seepage, the paper simulated the saturated-unsaturated transient seepage field under the condition of rainfall, and analyzed the influence of rainfall intensity, rainfall duration and saturated permeability coefficient on the stability of the unsaturated land slope. The results indicate that the slope safety coefficient is increased with the increase of rainfall intensity, and decreased with the increase of saturated coefficient. Because it is raining, rainfall infiltration quantity was increasing, matrix suction was losing gradually, pore water pressure is increasing gradually, thus land slope safety coefficient is decreased with the increase of raining time.