Abstract: To meet the demand for precise control of porous copper pore structures in the field of electronic device heat dissipation, three types of water-atomized copper powders (near-spherical powders (S-powder), irregular powders (L-powder), and cluster-shaped powders (U-powder)) were used as the raw materials. Porous copper samples were fabricated by metal injection molding (MIM) combined with powder sintering at 850 ℃, 900 ℃, and 1000 ℃. The effects of copper powder morphology and sintering temperature on pore characteristics, water absorption performance, sintering shrinkage behavior, and mechanical properties of porous copper were systematically investigated. The results show that under the identical sintering temperature, the samples prepared from U-powder possess the highest porosity, average pore size, water absorption rate, and sintering shrinkage, while the S-powder samples exhibit the lowest values of these parameters. With increasing sintering temperature, the atomic diffusion is enhanced, the porosity, average pore size, and water absorption rate of all samples decrease, whereas the linear shrinkage, volumetric shrinkage, and tensile strength increase remarkably. A significant positive correlation exists between the average pore size and water absorption rate. The U-powder samples sintered at 850 ℃ achieve the porosity of 44.3% and water absorption rate of 1.2 mm/s, and the tensile strength of S-powder samples sintered at 1000 ℃ reaches 117.6 MPa. Considering the application requirements for porous heat-dissipation materials (porosity≥30 %, tensile strength≥20 MPa), the U-powder porous samples sintered at 900 ℃ presents the best comprehensive performance, promising the application prospects in microelectronic heat-dissipation components.