In order to study the influence of stress and excited magnetic field on the magnetization and magnetic output of ferromagnetic materials, this study deduced the differential relationship model between magnetization and stress under constant excited magnetic field and the differential relationship model between the magnetization and excited magnetic field under constant stress condition,respectively, based on J-A theoretical model. The above models were verified by numerical simulation and experiment. The results show that the magnetization increases firstly and then decreases with the increase of the stress under the constant excited magnetic field, and the magne-tization increases with the increase of the excited magnetic field under the constant stress. In order to verify the correctness of the two above models, the corresponding verification experiments were designed to verify the relationship between magnetic output and stress under the constant excited magnetic field, and the relationship between magnetic output and excited magnetic field under the constant stress, respectively. The experiment results are consistent with the theoretical calculation results. This study provides a theoretical reference for the study of the physical mechanism of the stress-test by magnetic method, and guide the new thinking on the magneto-mechanical effect.