Based on the working principle of vibratory excavation of hydraulic excavator, the expression of digging resistance changed with time under sine wave inspiritment was deduced; a comparison analysis was given after calculating the forces status of rock and soil under static load and vibratory load respectively by using MATLAB; and then RFPA-2D(rock failure process analysis code) was used to make comparison of simulation experiment on rock and soil failure process under static load and vibratory load. The results demonstrate that, compared with the normal excavation under the same situation, the digging resistance and the energy consumption can be reduced by respectively 30% and 60% at maximum, and that the working efficiency can be increased by 45% at maximum owing to vibratory excavation.