3D printed cement-based materials decreases interstrip contact surface properties due to the stack molding process. Metakaolin can reduce porosity and improve mechanical property,but its high water demand cause water loss on the surface of printing strip,and the interlayer bonding performance decline. Limestone powder has a dilution effect,which can improve the high water demand of metakaolin. The influences of metakaolin and mixed limestone powder on anisotropic performance of 3D printed cement-based materials were studied,and the mechanism from a microscopic perspective was explained. The results show that the optimal mass content of metakaolin is 12%,and the optimal mixing mass ratio is m(metakaolin)∶m(limestone powder) is 2∶1. After adding metakaolin,the fluidity of 3D printed cement-based materials decreases significantly,the fluidity of mixed limestone powder increases. The compressive strength of 3D printed test block is characterized by X>Z>Y>molding,and the variation pattern of flexural strength in different directions is basically the same as the compressive strength,with anisotropic characteristics.