The combined technology of inertial friction welding and isothermal deforming was utilized to prepare IMI834/Ti6246 dual titanium alloy scaled disk. The effect of isothermal deforming on the microstructure and property of inertial friction welding IMI834/Ti6246 dual titanium alloy scaled disk was analyzed. The results show that the inertial friction welding forms the fine microstructure in the welding seam of IMI834/Ti6246 dual titanium alloy, meanwhile results the coarse microstructure of heat affect zone on both sides. The ultrasonic nondestructive testing indicateds that there are some defects in local zone of welded dual titanium alloy scaled disk. After isothermal deforming, the residual inertial defects after inertial friction welding are effectively eliminated and the coarse microstructure of heat affected zone both sides is obviously improved which homogenizes the transition zone between welding seam and both sides. The weld steam of inertial firction welded IMI834/Ti6246 dual alloy scaled disk was effectively strengthened during isothermal deforming. The inertial friction welding and isothermal deforming could be combined to prepare high performance dual titanium alloy disk.