Graphene-based　terahertz(THz)metasurfaces　combined　with　metallic　antennas　have　the　advantages　of　ultra-small　thickness,electrical　tunability,and　fast　tuning　speed.However,their　tuning　ability　is　limited　by　non-independently　tunable　pixels　and　low　modulation　depth　due　to　the　ultra-small　thickness　of　graphene.Here,we　demonstrate　a　reconfigurable　THz　phase　modulator　with　5×5　independently　tunable　units　enabled　by　switch-ing　the　voltages　applied　on　10　graphene　ribbons　prepared　by　laser　cutting.In　addition,by　introducing　quasi-bound　states　in　the　continuum　resonance　through　a　designed　double　C-shaped　antenna,the　efficiency　of　the　device　is　enhanced　by　2.7-3.6　times　under　different　graphene　chemical　potentials.Experimental　results　demon-strate　that　a　focus　can　be　formed,and　the　focal　length　is　changed　from　14.3　mm　to　22.6　mm.This　work　provides　potential　for　compact　THz　spatial　light　modulators　that　may　be　applied　in　THz　communication,detection,and　imaging.