Kenaf　geopolymer　for　3D　printing　is　a　promising　representative　for　comprehensive　and　intelligent　utilization　of　industrial　and　agricultural　wastes.　Aiming　at　exploring　the　effect　of　raw　materials＇　proportion　on　printing　performances,　alkali　activator　dosage　(10　wt.%,　15　wt.%,　20　wt.%)　and　mass　ratio　of　ground　granulated　blast　furnace　slag　(GGBFS)　to　fly　ash　(FA)　(15:85,　20:80,　25:75)　were　adopted　as　main　variables　in　this　paper.　Results　have　shown　that　increasing　the　activator　dosage　and　decreasing　the　mass　ratio　of　GGBFS　to　FA　can　improve　the　flowability,　and　adjusting　these　two　parameters　can　tailor　the　fluidity　to　a　suitable　range.　Moreover,　dry　density　of　kenaf　geopolymer　was　more　significantly　affected　by　alkali　activator　dosage　compared　with　mineral　powder　ratio,　and　lightweight　characteristic　due　to　kenaf　participation　effectively　improved　shape　retention　ability　of　printed　specimens.　Besides,　microstructure　analysis　further　confirmed　that　with　appropriate　alkali　activator　dosage　and　mineral　powder　ratio,　high　level　of　geopolymerization　reaction　can　be　achieved　to　produce　enough　gel　product　for　a　satisfactory　internal　structure,　which　externally　manifested　as　excellent　printability　and　mechanical　strength.　Finally,　formula　with　alkali　activator　dosage　of　15　wt.%　and　GGBFS　to　FA　mass　ratio　of　25:75　was　recommended　for　satisfactory　printing　performance　and　mechanical　properties.