Abstract: Amorphous alloy and oriented silicon steel composite core can combine the advantages of traditional pure amorphous alloy and pure oriented silicon steel cores, which has a broad application prospect in the domain of distribution transformer core. Analysis of the excitation characteristics of the composite core containing two nonlinear soft magnetic materials is a prerequisite for optimal design of its structure. First, the equivalent circuit model of the composite core under the open circuit excitation condition is established, and its circuit voltage equation is written according to Kirchhoff's second law. Then, the equivalent dual nonlinear magnetic circuit model is established according to the structural features of the composite core, and its magnetic circuit equations are written based on the principle of continuity of magnetic flux and Ampere's circuital law. Again, the magnetic circuit equations are coupled to the magnetomotive force term in the circuit voltage equation according to the derivative transformation, and the Jiles-Atherton hysteresis model is used to characterize the nonlinear magnetization characteristics of amorphous alloy and oriented silicon steel, and thus a dual nonlinear circuit-magnetic coupling model is established for composite core considering hysteresis effect. Finally, based on this proposed coupling model, the excitation current, flux density distribution and no-load loss of the composite core are solved, and the accuracy of the proposed method is verified by comparing with the experimental results.