Based on the elasticity mechanical model, we employ the free_state bilayer magnetoelectric nano_thin film model which introduces the magnetoelectric （ME） theoretical voltage coefficient formula simply. By this way, the ME voltage coefficient of CoFe2O4/Pb （Zr0．52Ti0．48）Ｏ3 bilayer has been calculated and analyzed under the corresponding material parameters. The results show that the ME voltage coefficient is reduced significantly when the thickness of substrate increases due to the gripping effect. The optimum volume ratio of piezoelectric film and magnetoelectric film increase when the gripping effect increasing.