The magnetoelectric effect of layered NFO/BTO composite films was studied based on the mechanical parameter model. It was found that the magnetoelectric coupling performance was best when the volume fraction of piezoelectric phase was about 0.47. The 2-2 NFO/BCZT films with different volume fraction ratios were grown by pulsed laser deposition with 0.7%Nb (001)-STO substrates. The results of XRD show that NFO/BCZT composite films are (00l) preferentially grown. The magnetoelectric coupling coefficient of the NFO/BCZT composite film was measured by a lock-in amplifier, the results show that the magnetoelectric performance is best when the volume of piezoelectric phase is slightly larger than that of piezoelectric phase.There are some differences between experimental results and theoretical results, which be mainly due to the difference between the actual parameters of the material and the parameters used in the calculation,the failure to obtain accurate k values due to the non-ideal coupling of the interface, and magnetoelectric effect is affected by microstructure and stress of thin films.