<p>This study investigates the morphology, microstructure characteristics, and forming mechanism of dissimilar zirconium alloy during current-induced solid-state welding under different currents. The temperature field, current density distribution, strain and strain rate distribution, and material flow behavior are thoroughly discussed using numerical simulation methods. The results indicate that significant differences exist in the morphology and microstructure of current-induced solid-state welded joints under various current conditions. When the current is low, the joint fractures at the weld position, whereas with higher current levels, the joint fractures at the cladding tube, reaching a maximum tensile force of 8373 N. The fracture mode of all joints is ductile fracture mode. The numerical simulation results indicate that as time increases, the joint temperature rapidly rises, resulting in the formation of a localized overheat zone in the lower part of the end plug cladding pipe interface. The current density at the interface between the end plug and cladding tube reaches its peak during the initial welding stage, followed by a gradual decrease. Moreover, the maximum strain rate decreases as welding time increases. Additionally, as the current increases, the joint temperature noticeably rises. Simultaneously, the region characterized by high strain and high strain rate expands rapidly.</p>