Abstract: In order to meet the increasingly high performance requirements of nickel-based superalloys for the hot-end components of aerospace engines, carbon nanotubes-graphene nanosheets(CNTs-GNPs)/K418 composites were prepared using selective laser melting (SLM) technology. Through the L₉ (3⁴) orthogonal experiment, the effects of laser power, scanning speed, scanning interval, and powder layer thickness on the forming quality and mechanical properties were studied. Based on the energy density, the correlation mechanism between process parameters and the structure and properties of the printed parts was revealed. The results show that under the process parameters in the paper, the larger the laser power and scan spacing, and the smaller the scan speed and powder layer thickness, the higher the tensile strength; laser power has the most significant effect on the average tensile strength, with the order of influence being: laser power > powder layer thickness > scan speed > scan spacing. Excessively high energy density (141.7 J/mm³) combined with small scanning spacing can lead to pores and cracks due to intensified Marangoni convection and concentrated thermal stress. Excessively low energy density (≤37.9 J/mm³) results in lack of fusion and increased porosity. When energy density is 95.8 J/mm³, there are no obvious defects in the sample; the cross-section forms a continuous honeycomb-like cell structure, and the longitudinal section shows typical columnar crystal-oriented growth, with tensile strength reaching 934.5 MPa. The research results in the paper can provide process support for the additive manufacturing technology of high-performance high-temperature components.