Abstract: Through indoor excavation test of soil slope, slope deformation and stress variation under the affects of load and excavation were studied. The stress-strain mechanism leading to instability of the slope was discussed through numerical simulation. The effect of excavation on the stability coefficient of the slope was analyzed. The results show that the stability coefficient of the slope will reduce under load at slope top and excavation at stope toe. Under initial condition, the coefficient is 1.84, and decreases to 1.322 under the load of 120kg. After 15cm excavation, the coefficient decreases to 1.093, and the slope is on the edge of instability. The stress variation of the slope is maximal in the part near the load and decreases away from the load area. Vertical stress gradually reduces as a result of excavation.