In this present study the double layers structure model of extended Korteweg-de Vries(K-dV) equation will be obtained with the help of the reductive perturbation method, which admits a double layer structure in current plasma model. Then by using of new analytical method we obtain the new exact solitary wave solutions of this equation. Double layer is a structure in plasma and consists of two parallel layers with opposite electrical charge.The sheets of charge cause a strong electric field and a correspondingly sharp change in electrical potential across the double layer. As a result, they are expected to be an important process in many different types of space plasmas on Earth and on many astrophysical objects. These nonlinear structures can occur naturally in a variety of space plasmas environment. They are described by the Korteweg-de Vries(K-dV) equation with additional term of cubic nonlinearity in different homogeneous plasma systems. The performance of this method is reliable, simple and gives many new exact solutions. The (G'/G)-expansion method has more advantages: It is direct and concise.