Abstract: This study employed electromagnetic pulse welding (EMPW) to join 6061Al and T2Cu as dissimilar materials. The effects of discharge energy on interface morphology, wave formation mechanisms, and element diffusion were systematically investigated through numerical simulations and experiments. It was shown that the increase in discharge energy increased the electromagnetic force on 6061Al and increased the collision velocity, while the collision angle was not affected. The interface morphology changes from a flat interface to an irregular wave interface and a shear wave interface, and finally to a transition layer, with the amplitude increasing from 1.55 μm at 21 kJ to 4.61 μm at 36 kJ. Waveform formation continues as the impact continues, the bumps increase in size and become embedded in each other, gradually forming a waveform structure, and the collision point moves forward to produce new bumps. Element diffusion occurs at the interface with or without the transition zone, and the maximum shear strength of the joint is 10730 N. The higher the energy leads to metallurgical bonding between the parent materials, which improves the mechanical properties.