A new artificial boundary model is proposed based on conventional viscous-spring artificial boundary model. Firstly, the stress formula on artificial boundary are derived based on the wave propagation theory and the new artificial boundary model is constructed by adding the nodal force to conventional viscous-spring on the boundary of finite field, which could include the effect of lateral boundary displacement. And then the values of the stiffness, the damp and nodal force are deduced based on stress wave theory. Finally, a numerical example is given to verify the proposed model. Compared with viscous-spring artificial boundary, this proposed artificial boundary model possesses the merits of same efficiency and conciseness, but higher precision than conventional viscous-spring artificial model.