Electrochemical　conversion　of　hypertoxic　trivalent　arsenic　to　value-added　metallic　arsenic　can　not　only　contribute　to　pollution　abatement,　but　also　resources　reutilization,　therefore　being　widely　explored.　Electrochemical　reduction　of　trivalent　arsenic　as　a　promising　way　is　widely　explored.　However,　the　high　efficiency　conversion　is　retarded　by　the　sluggish　reduction　kinetics　of　AsO33−　and　fierce　evolution　of　side　products　of　both　H2　and　toxic　AsH3.　Herein,　by　using　the　sodium　citrate　as　the　additive,　the　current　efficiency　for　metal　arsenic　production　is　increased　greatly　from　60%　to　91%,　with　the　accompanied　evolution　of　hypertoxic　AsH3　being　restrained　from　0.15　Nm3/tAs　to　0.022　Nm3/tAs,　promising　a　high-efficiency　and　green　process.　The　electrochemical　tests　and　electrode　surface　characterizations　as　well　as　DFT　calculations　indicate　that　the　added　sodium　citrate　promotes　both　the　diffusion　of　reactive　AsO33−　towards　the　cathode　and　its　subsequent　adsorption　on　the　Ti　cathode,　contributing　to　smoother　reduction　for　generating　metal　arsenic,　with　the　evolution　of　toxic　AsH3　being　hindered　at　the　same　time.　The　results　can　provide　new　insights　for　the　high-efficiency　and　greener　conversion　of　hypertoxic　trivalent　arsenic　to　value-added　metallic　arsenic.　©　2024