Abstract: A universal power adapter to allow only the plug desired to stick out smoothly in a simple construction and allowing convenient operation is comprised of a lid, a base, a rotary switch, and multiple plugs; multiple channels being disposed on the external wall of the base, a standardized plug being inserted to each channel; a rotary switch containing a bar sliding block and a braking pushbutton; the bar sliding block containing a bar slide and a gap; the pushbutton being inserted into the gap; a protruding block and a slot below being disposed to the top of the plug; the slot receiving the insertion end of the braking pushbutton; and the pushbutton sliding in the channel on the external wall of the base; and the protruding block of each plug being inserted into the bar slide of the bar sliding block to slide against the protruding block.