Solar absorber is a key device that converts solar irradiation into heat via photothermal conversion, which has potential applications in solar thermal power systems, and seawater desalination. In this paper, we propose a wide-angle, broadband and polarization insensitivity metamaterial solar absorber based on titanium nitride (TiN). Numerical results show that this solar absorber has a total average spectrum absorption of up to 97.5% at wavelength of 300–2500 nm. Based on the distributions of the electric and magnetic field, it is believed that the coupling resonance of surface plasmon resonance, guided mode resonance and cavity resonance is responsible for its excellent absorption of solar energy. Furthermore, we discuss the effects of incidence angle on the solar absorber and demonstrate that the average spectrum absorption of more than 85% can be obtained even at a large incidence angle of 60°, and it is insensitive to the change of polarization angle. The effect of geometric parameters of the solar absorber on spectrum absorption performance was investigated. This research will provide new ideas for the design of solar thermophotovoltaic and thermal conversion systems. [ABSTRACT FROM AUTHOR]