For the purpose of describing the strongly nonlinear output of Giant Magnetostrictive Material (GMM), the J-A Model and Z-L Model are introduced based on a detailed analysis of the magnetic field intensity distribution inside the GMM stick, and a better dynamic output model is established. The static output properties of the GMM stick are forecasted, the influence of pre-pressure, bias field and exciting field to the output properties are studied. Moreover, the influence of frequency is discussed, indicating that in the case of high-frequency driving, the eddy current loss and abnormal loss should be taken into consideration carefully. The consequence of this analysis provides a theoretical support to the optimization and property forecast of the GMM instruments.