Hi, @shanren
If you will be using 5V thought your whole project then @J-M-L answer is correct with a decent 5Vdc power supply.
BUT
If you are going to supply your project through the DC socket on the UNO, then NO, the internal 5V regulator on the UNO cannot supply much more current than for the UNO board and one or two peripherals.
Tom... 
