Sodium　metal　anodes　have　received　considerable　attention　due　to　their　high　theoretical　capacity,　low　reduction　potential,　and　natural　abundance　in　sodium　batteries.　Nevertheless,　uneven　sodium　ion　(Na+)　deposition　accelerates　uncontrolled　dendrite　growth　and　an　unstable　solid　electrolyte　interphase　(SEI)　layer　hinders　Na+　diffusion,　which　eventually　leads　to　short　circuits　and　potential　safety　hazards.　Herein,　a　multiphase　artificial　interphase　layer　composed　of　sodium　bismuth　alloy　(BiNa3)　and　sodium　chloride　(NaCl)　is　applied　to　improve　the　interface　stability　of　sodium　metal　anodes.　Theoretical　calculations　and　experimental　results　demonstrate　that　the　BiNa3　alloy　with　good　sodiophilic　properties　can　function　as　nucleation　sites　to　lower　the　nucleation　barrier,　induce　uniform　Na+　flux,　and　guide　dendrite-free　Na　deposition.　Meanwhile,　a　NaCl　compound　with　high　ionic　conductivity　can　lower　the　Na+　diffusion　barrier　and　improve　diffusion　kinetics.　As　a　result,　the　assembled　symmetric　cells　with　a　sodium　metal　anode　modified　by　using　a　multiphase　artificial　interphase　layer　exhibit　a　remarkable　cycling　performance　of　1200　h　with　a　low　overpotential　of　20　mV　at　3　mA　cm-2　and　3　mA　h　cm-2.　The　full　battery　assembled　with　the　Na3V2(PO4)3　cathode　retains　an　ultrahigh　capacity　of　99　mA　h　g-1　even　after　1000　cycles　at　5C.　The　design　strategy　for　a　multiphase　artificial　interphase　layer　can　provide　insight　into　developing　high-performance　and　dendrite-free　sodium　metal　batteries.　A　multiphase　artificial　interphase　layer　can　induce　homogeneous　deposition　of　Na+　and　promote　rapid　transport　of　Na+.　Therefore,　the　BiCl3-Na　anode　achieves　uniform　dendrite-free　deposition　and　improves　electrochemical　performance.