A　scheme　is　presented　for　realizing　an　N-qubit　quantum　phase　gate　with　trapped　ions.　Taking　advantage　of　the　virtual　excitation　of　the　vibrational　mode,　the　qubit　system　undergoes　a　full-cycle　of　Rabi　oscillation　in　the　selective　symmetric　Dicke　subspace.　The　scheme　only　involves　a　single　step　and　the　operation　is　insensitive　to　thermal　motion.　Moreover,　the　scheme　does　not　require　individual　addressing　of　the　ions.