With asymptotic assumption for physical field near notch tip, characteristic differential equations for electroelastic singularities of wedges that contain bounded piezo/piezo materials are built from three-dimensional equilibrium equations and Maxell equations. Mechanical and electric boundary conditions are expressed by combination of singularity orders and characteristic angle functions. Thus, evaluation of singularity orders is transformed into solving ordinary differential equations (ODEs) under designated boundary conditions. Interpolating matrix method is introduced to solve derivative ODEs. More electroelastic singularity orders and associated eigenfunctions in wedges that comprise two bounded transverse isotropic piezoelectrics materials are obtained. It shows that the method is efficient and has high accuracy compared with existent solutions.