Barium hexagonal ferrite BaZn 2 Fe 16 O 27 was rapidly synthesized by adsorbent combustion method. The whole preparation time was controlled within 8h. The microstructures were studied using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FT–IR). The results showed that the pure BaZn 2 Fe 16 O 27 was obtained after calcined at 1200°C and the particles exhibited homogeneous hexagonal-plate shape with high aspect ratio. Moreover, the complex permeability (μr=μ′-jμ″) and the complex permittivity (εr=ε′-jε″) were measured in the frequency range of 8–12GHz (X-band) and 12–18GHz (K u -band) using the network analyzer. The as-prepared ferrite exhibited strong magnetic loss properties. The microwave absorbing properties of the single BaZn 2 Fe 16 O 27 ferrite layer with different thicknesses were also analyzed. The results showed that the minimum reflection loss was −15.3dB and the bandwidth of reflection loss less than −10dB reached 7.7GHz with the absorber thickness only 1.7mm. The adsorbent combustion method is a kind of ideal method to rapidly prepare barium hexagonal ferrite with excellent microwave absorbing properties.