To improve electromagnetic wave (EMW) absorption performance, a novel nano-laminated Dy3Si2C2coating was successfully in situ coated on the surface of SiC whisker (SiCw/Dy3Si2C2) using a molten salt approach. A labyrinthine three-dimensional (3D) net was constructed by the one-dimensional (1D) SiCwcoated with the two-dimensional (2D) Dy3Si2C2layer with a thickness of ~100 nm, which significantly improved the EMW absorption properties of SiCw. Compared to pure SiCwwith the minimum reflection loss (RLmin) value of −10.64 dB and the effective absorption bandwidth (EAB) of 1.04 GHz for the sample with a thickness of 4.5 mm, SiCw/Dy3Si2C2showed a significantly better EMW absorption performance with RLminof −32.09 dB and wider EAB of 3.76 GHz for thinner samples with a thickness of 1.76 mm. The enhancement of the EMW absorption performance could be ascribed to the improvement of impedance matching, enhanced conductance loss, interfacial polarization as well as multiple scattering. The SiCw/Dy3Si2C2can be a candidate for EMW absorber applications due to its excellent EMW absorption performance and wide EAB for relatively thin samples, light weight, as well as potential oxidation and corrosion resistance at high temperatures.