The key of transformer protection is to distinguish magnetic inrush from fault current. Effective simulations for magnetic inrush and fault current of transformer are the foundation of right division. In this paper, based on the study on the model of electrical transformer in EMTDC (Electro-Magnetic Transient in DC System), the simulations for magnetic inrush and fault current of three-phase transformer are done. And analysis are given to the simulation. The results show that EMTDC can effectively simulate the magnetic inrush and fault current of transformers under different conditions.