The mechanical system and hydraulic system of an excavator were built using the software of Pro/E and ADAMS （Automatic Dynamic Analysis of Mechanical Systems）. The integration of the two systems established the hydraulic-hydraulic virtual robotic excavator model through parameter correlation technology under ADAMS environment; and a large amount of kinematic and dynamic simulations were carried out. The results offer certain reference for predicting the feasibility of the design plan and trial-production of the physical prototype. The method has important theory and engineering meaning for its improving the speed and precision of product development; and reducing the development cost.