Three-dimensional　concrete　printing　is　a　promising　technology　and　attracts　the　significant　attention　of　research　and　industry.　However,　printable　and　mechanical　capacities　are　required　for　3D　printable　cementitious　materials.　Moreover,　the　quantitative　analysis　methods　of　printable　performance　are　limited　and　have　low　sensitivity.　In　this　study,　the　orthogonal　experiment　through　samples　combining　3D　concrete　printing　method　with　fly　ash,　silica　fume,　and　ground　granulated　blast　furnace　slag　was　designed　to　obtain　the　printable　and　mechanical　property　influence　of　various　mix　proportions.　Furthermore,　multiple　industrial　wastes　were　utilized　to　improve　material　sustainability.　Meanwhile,　the　static　and　dynamic　extrusion　pressure　measured　by　the　original　3D　printing　extrudability　tester　were　verified　to　achieve　a　high-sensitivity　evaluating　indicator.　Thereby,　a　novel　high-sensitivity　quantitative　analysis　method　of　printable　capacity　was　established　to　explore　the　influence　of　industrial　wastes　usage　on　the　printability　of　3D　printable　mortars.　The　optimum　dosage　of　fly　ash,　silica　fume,　and　ground　granulated　blast　furnace　slag　was　20　wt.%,　15　wt.%,　and　10　wt.%,　respectively,　based　on　printable　and　mechanical　property　experiments.　Furthermore,　the　optimum　dosage　was　employed　to　print　the　sample　and　achieved　a　higher　compressive　strength　(56.3　MPa)　than　the　control　cast.