In　this　study,　AgBr/Ag2CO3　heterojunction　photocatalysts　were　synthesized　by　an　in　situ　growth　method　under　different　pH　conditions.　The　crystal　phases,　microstructure,　visible　light　absorption,　and　photocatalytic　performance　of　AgBr/Ag2CO3　heterojunctions　were　characterized　in　detail.　The　results　showed　that　AgBr/Ag2CO3　heterojunctions　could　enhance　photocatalytic　activity,　compared　with　pure　AgBr　and　Ag2CO3.　In　addition,　pH　conditions　in　the　synthetic　process　cause　a　distinct　change　for　photocatalytic　activity　of　AgBr/Ag2CO3　heterojunctions　because　of　the　influence　on　the　crystallinity.　The　AgBr/Ag2CO3　heterojunction　synthesized　at　pH　=　9　had　the　highest　photocatalytic　activity,　and　the　degradation　rate　of　rhodamine　B　(Rh　B)　solution　was　98.93%　within　20　min.　Furthermore,　the　synthesis　mechanism　and　photocatalytic　mechanism　were　both　analyzed.