A theoretical magnetic field intensity model within giant magnetostrictive material was presented. This model was established just like the reluctance model, while could describe the non-uniform distribution flexibly for its integral form. This model employed magnetic circuit theorem calculating the mean of the magnetic field, while used a normalized function describing the distributing character. The distributing function was determined by Biot–Savart law and relative permeability of the material. The model was validated with the help of the experimental device. At last, the fitting degree of the model with the tested results in predicting the performance of the actuator is researched.