A nonlinear time domain dynamic model is established based on the J-A theory for the ship high voltage transformer, the eddy current loss is also taken into account , this model accurately reflects the hysteresis and saturation characteristics of transformer core, and does well in describing the dynamic process of transformer, it can be used to design the ship transformer or the study of relay protection related, using a fourth-order Runge-Kutta algorithm for solving nonlinear differential equations to ensure the model has a high accuracy, established the pre-magnetizing model, the transformer no-load closing simulation results verified the correctness of the transformer model.