The　origin　of　distinguished　oxygen　evolution　reaction　(OER)　catalytic　properties　of　multi-principal　element　alloys　(MPEAs)　is　not　clear　yet　due　to　the　rich　surface-active　sites　may　exist　in　MPEAs　composed　of　multiple　types　of　elements,　which　may　bring　complex　catalytic　environment.　In　this　work,　four　main　steps　were　carried　out　using　computational　materials　science.　The　atom　distribution　of　bulk　MPEAs　was　constructed　firstly　based　on　the　previously　predicted　site　preference　of　atoms　occupying　sublattices,　which　is　beyond　the　traditional　hypothesis　that　the　atom　distributing　randomly　on　the　whole　lattice.　Then　the　(111)　close-packed　surface　slab　of　CoFeGaNiZn　MPEA　was　obtained　by　cleaving　the　bulk　structure.　Subsequently,　the　OER　processes　were　systematically　explored　by　calculating　the　free　energy　change　of　intermediates　*OH,　*O,　and　*OOH　at　171　adsorption　sites　on　the　(111)　surface.　Finally,　the　oxygen　evolution　reaction　catalytic　mechanism　and　its　site　preference　behavior　of　FCC_CoFeGaNiZn　MPEA　were　discussed　in　detail.　The　results　show　that　atoms　have　obvious　site　preference,　which　deviating　the　ideal　randomly　distribution,　especially　Co,　Fe　and　Zn　atoms　always　prefer　to　3c　sublattice　at　all　temperature,　Ga　atoms　tend　to　favor　1a　sublattice,　and　the　site　preferences　of　Ni　atoms　and　Ga　atoms　are　affected　by　the　heat　treatment　temperature.　At　1273　K,　the　site　occupying　configuration　is　(Co0.0246Fe0.01680Ga0.4550Ni0.4990Zn0.0046)1a　(Co0.2580Fe0.2610Ga0.1150Ni0.1000Zn0.2650)3c.　The　(111)　surface　of　FCC_CoFeGaNiZn　MPEA　was　based　on　the　site　occupying　configuration　at　1273　K,　and　it　was　then　supposed　to　quenched　to　ground　state　to　simulate　the　experimental　status　in　the　available　literature.　Since　*O　at　hollow　sites　transforms　into　*OOH　at　a　higher　overpotential,　hollow　sites　may　be　poisoning　surface　sites.　Three　intermediates　are　found　to　primarily　participate　in　the　catalytic　reaction　on　top　sites.　In　addition,　there　are　no　scaling　relationships　between　Delta　E*OH　and　Delta　E*O　for　CoFeGaNiZn　MPEA,　even　for　the　same　type　of　top　sites.　It　is　noteworthy　that　an　average　overpotential　of　0.349　V　was　predicted　by　considering　the　combinations　of　three　intermediate-tendency　elements,　which　is　in　better　agreement　with　the　experimental　overpotential　of　0.37　V　at　10　mA/cm2　current　density　than　the　overpotential　of　0.28　V　based　on　the　special　quasirandom　structures　(SQS).　Current　intensive　explorations　bring　new　insights　into　the　OER　catalytic　mechanism　of　the　preferred　adsorption　sites　of　MPEAs　based　on　the　reasonable　consideration　concerning　the　atoms　distributing　configuration　involving　the　exact　site　preference　of　the　constituent　metallic　atoms　on　the　sublattice.