A grating-type ultra-wide-band solar absorber was designed based on the refractory titanium nitride (TiN) and titanium dioxide (TiO₂). The absorption characteristics of this absorber were studied using the finite element method and the effects of its structural parameters, working wavelength and incident angle on its absorption performance were analyzed. The results show that the absorption characteristics can be effectively controlled by adjusting the structural parameters. In the wavelength range of 500-2000 nm and the incident angle range of 0°-75°, the absorption efficiency is larger than 80%, indicating that the designed absorber possesses the characteristic of ultra-broadband absorption. In addition, the top layer of the unit structure adopts a hemispherical structure, which can increase the average absorption rate of the absorber. The absorber designed in this paper has a potential application prospect in the thermo-photovoltaic and other fields.