Abstract Hybrid core/shell Ni/TiO2 composites were prepared with different contents of tetrabutyl orthotitanate (TBOT). The microwave absorption properties of the Ni/TiO2 composites have been studied in the range of 1–18GHz. The amount of TiO2 is found to have a great impact on the microwave absorption of this metal–semiconductor composite. The microwave absorption properties of Ni/TiO2 heterostructure prepared at 2mL TBOT were highly enhanced compared with other two samples. The excellent microwave absorption properties are due to the proper complementarities between magnetic loss and dielectric loss, geometrical effect, the natural resonance and multipolarization. The multiple dielectric resonances are attributed to interfacial polarization and the magnetic resonances are ascribed to natural resonance.