This paper proposes a new and unprecedented strategy for designing efficient and ultra-light electromagnetic wave (EMW) absorbing materials. The strategy utilizes a nano-antenna arrays structure to capture EMW. Specifically, CoNi-layered double hydroxide (CoNi-LDH) nanoneedles are designed on the surface of carbon fiber cloth (CFC) using a solvothermal method, whereafter an in situ chemical oxidative polymerization process is employed to construct polyaniline (PANI) coating on these CoNi-LDH nanoneedles. The resultant composite, named PANI@CoNi-LDH@CFC, possesses the unique shell-core PANI@CoNi-LDH nano-antenna arrays and thus exhibits enhanced EMW absorption performance. The PANI@CoNi-LDH@CFC composite obtains an effective absorption bandwidth of 14.8 GHz (1.0–5.0 mm) and a minimum reflection loss of −57.6 dB. In particular, computer simulation technology confirms that the radar cross section values of PANI@CoNi-LDH@CFC are lower than −16.4 dBm2 in the range of −60°<θ < 60°, indicating a high radar wave attenuation ability. This work pioneers the research on design of nano-antenna arrays structure to strengthen EMW capture and opens up a unique path for constructing high-performance EMW absorbing materials.