Abstract: Continuous fiber reinforced polymer composites (CFRPC) possess outstanding mechanical properties, corrosion resistance and lightweight characteristics, and thus have been widely applied in various fields. However, due to interlaminar defects inherent to the layer-by-layer deposition process are attributed to the insufficient interlaminar mechanical properties of 3D printed CFRPC, CFRPC is prone to delamination failure. That makes the structural properties become unstable, increases the risk of design and use, and limits its applications in high-tech fields. In this study, continuous basalt fiber/polyamide composites modified with graphene oxide (GO) and carbon nanotubes (CNTs) were fabricated by fused filament fabrication technology and studied. The addition of 0.8wt% GO increased the transverse tensile strength of CFRPC by 111.2%, the transverse tensile modulus by 184.3%, the interlaminar shear strength by 24.2%, and the mode II interlaminar fracture toughness by 174.2%. The addition of 1.5wt% CNTs increased the transverse tensile strength of CFRPC by 34.2%, the transverse tensile modulus by 135.8%, the interlaminar shear strength by 18.1%, and the mode II interlaminar fracture toughness by 165.1%. Combined with SEM image analysis, lamellar GO improved the inter-layer properties by enhancing the interfacial chemical bonding, having the aid of wrinkle structure, and forming three-dimensional continuous networks; on the other hand, tubular CNTs improved the inter-layer properties of CFRPC by preventing the entanglement of molecular chains and bridging. Through multi-scale collaborative reinforcement design, matrix strength and interface strength enhancements and crack propagation path regulated by nanofillers were clarified as the strengthening mechanisms. This study provides a theoretical basis for the development of high-performance 3D printed composite materials which have important application potential in aerospace, automotive manufacturing and other fields.