Coral　sand　is　characterized　by　the　unique　properties　different　from　conventional　sediments.　To　investigate　the　horizontal　bearing　characteristics　of　2　x　2　pile　groups　in　coral　sand　foundation,　a　series　of　centrifuge　model　tests　were　conducted,　focusing　on　the　effects　of　pile　spacing　and　vertical　dead　loads.　In　this　study,　the　load-displacement　responses,　bending　moments,　lateral　deflections,　and　axial　force　variations　were　measured.　Additionally,　soil　resistance,　p-y　curves,　and　p-multipliers　were　calculated　and　analyzed.　Results　show　that　increasing　pile　spacing　from　3　to　5D　and　7D　enhanced　the　bearing　capacity　of　the　pile　group　by　24.7%　and　77.0%,　respectively.　Compared　to　the　leading　pile,　the　rear　pile　exhibited　reduced　bending　moments,　increased　lateral　displacements,　and　lower　soil　resistance　and　p-multipliers　due　to　pile-soil-pile　interaction　and　the　shadowing　effect.　Furthermore,　the　applied　vertical　dead　load　amplified　the　lateral　displacement　and　bending　moments　of　pile　due　to　the　P-Delta　effect　while　enhancing　soil　resistance　and　increasing　p-multipliers　through　vertical　compression.　These　findings　provide　valuable　insights　for　future　experimental　and　theoretical　research　on　pile　groups　in　coral　sand　foundations.