SiC nanowires exhibited great electromagnetic absorbing property while decorated in porous ceramic skeletons. However, the ceramic skeletons used in former researches always had multi-mode pore structure, so the effects of skeleton pore size on the properties of SiC nanowires could not be researched independently. In this work, porous SiC ceramics with single-mode pore distribution and controllable pore size were applied to prepare SiC nanowires/SiC composites. While the skeleton pore size was decreased from 13.94 μm to 2.18 μm, the SiC nanowires turned from straight to curved. Compared with the straight nanowires, the curved ones presented high-density stacking faults and large surface area, endowing the composites with superior electromagnetic absorbing property.