Abstract: Electromagnetic wave absorbers are increasingly required to combine strong attenuation, thin matching thickness, structural flexibility, and surface stability; however, conventional ceramic-based or particle-filled absorbers often suffer from insufficient flexibility, limited interfacial polarization, and poor impedance matching. Herein, flexible Mo2C/SiC/SiOx/C multiphase micronetwork films were fabricated by coaxial electrospinning followed by high-temperature carbothermal reduction. With increasing carbothermal reduction temperature, Mo2C gradually forms and the crystallinity of SiC is improved, leading to the formation of a hierarchical fibrous network composed of SiC, Mo2C, residual carbon, and amorphous SiOx phases. The optimized SCCM-4 sample obtained at 1550℃ provides abundant heterogeneous interfaces, continuous electron-transport pathways, and enhanced dipole polarization, thereby improving dielectric loss and impedance matching. As a result, the SCCM-4-derived powder/paraffin absorber delivers a minimum reflection loss of -63 dB at 1.66 mm and an effective absorption bandwidth of 4.0 GHz at 1.9 mm. Meanwhile, the freestanding SCCM-4 film maintains good flexibility and hydrophobicity, with a water contact angle of 134.2°. This work provides a feasible strategy for designing flexible ceramic-based multiphase micronetworks toward efficient electromagnetic attenuation and surface-stable electromagnetic protection.