With the help of Mathematica symbol calculation software, we extend the F/G expansion method improved by the G''/G expansion method and obtain exact solutions of a series of high dimensional nonlinear evolution equations by combining the variable separation method. Taking a (2+1)-dimensional dispersive long wave equation as an example, constructing the exact solutions by F/G expansion method is to extend the original traveling wave transform to any function transform, in which the traveling wave transform is only a special case of this any function transform. Then the non-traveling wave solutions of the (2+1)-dimensional dispersive long wave equation are obtained. By choosing the appropriate function, we can construct (2+1)-dimensional bright dromion solution and periodic solitary wave solution of the dispersion long wave equation. Then we study the propagation of the bright dromion solution with time and the evolution of the periodic solitary wave solution over time further.