In this paper, we investigated the microwave absorption properties of TiO2/Al2O3 ceramic composite as a function of three different concentrations of titanium dioxide TiO2 in the alumina matrix Al2O3. The aim of this study is to analyze the impact of TiO2 concentration on the complex dielectric properties as well as the microwave absorption capabilities of the composite in the X-band, using electromagnetic simulations. The results obtained show that the complex permittivity of the composite increases with increasing TiO2 concentration and decreases with increasing frequency, in the frequency range from 8.2 to 12.4 GHz. This variation indicates a significant dependence for the complex permittivity of the composite on TiO2 content and frequency. When the TiO2 concentration reaches 15% by volume in the composite, microwave absorption performance is optimized. More specifically, the composite exhibits a reflection loss bandwidth of less than − 10 dB (absorption greater than 90%) of 1.45 GHz, with a minimum reflection loss of -37.20 dB observed at the frequency of 10.70 GHz. The frequency band over which this optimum absorption occurs extends from 10.15 to 11.60 GHz. These results indicate that the TiO2/Al2O3 composite material with 15% TiO2 by volume possesses excellent performance characteristics for microwave absorption, making this material an excellent candidate for various technological applications. The composites studied may be particularly useful in the fields of electromagnetic shielding, electromagnetic pollution reduction and other applications requiring effective microwave control. Therefore, this study confirms that the addition of TiO2 in the Al2O3 matrix significantly improves microwave absorption properties, paving the way for new applications in electromagnetics.