The issue of energy has now risen as a key topic that human society needs to urgently address. Among these problems, solar energy is a common sustainable and environmentally friendly energy source. If solar energy is effectively tapped and applied, it can not only significantly reduce our dependence on conventional energy sources, but also help to alleviate the problem of environmental pollution. Solar absorber is an important component of solar energy utilization system that absorbs solar energy radiation and is essential to achieve high photothermal conversion efficiency. In this paper, a metamaterial solar absorber with a stacked circular nested cylinder is proposed, which is structured by a bottom metal and dielectric layer and a stacked circular nested cylinder in the upper layer. The absorption spectrum and electromagnetic field energy distribution of the absorber are studied and analyzed by the finite time domain difference method, as well as the effects of polarization angle and incidence angle on the absorption performance, and then analyzed by comparing the experiments for the effects of the structural dimensions of the absorber on the absorption rate. This design has potential application value in the field of solar energy absorption and utilization, and also provides research ideas for the design of broadband absorber. In summary, a solar absorber was designed by combining stacked and nested structures and its absorption characteristics were investigated. The FDTD method is used to investigate the effect of different geometrical parameters on the absorption properties. When applying the FDTD method to the calculation, the periodic boundary conditions in the x and y directions are set, while the boundary condition in the z direction is a Perfectly Matched Layer (PML), and the mesh step is set to be 10 nm. With regard to the dielectric constants of the materials, the dielectric constants of Ti, W, and SiO₂ are referred to the experimental values of Palik. The substrate of the designed absorber is chosen as the substrate of the absorber, which is the most suitable for the absorber. In this paper, the substrate of the absorber is chosen as Ti, and the thickness of Ti is chosen as 300 nm, mainly because the thickness exceeds the skinning depth of light in Ti, so that the transmittance of the incident sunlight is 0, and then the absorbance size of the absorber is only related to the reflectance size. Then the optimum dimensional parameters of the other parts of the absorber are determined, and the optimized optimum parameters are the period P=50 nm, the inner radius of the metal ring R₁=100 nm, the outer radius R₂=190 nm, the lower SiO₂ medium H₁=H₂=50 nm, the lower W-metal D=100 nm, the thickness of the upper metal ring t=d=40 nm, and the height of the medium cylinder h=220 nm. In order to analyze and verify the advantages of the stacked circular nested structure, comparative experimental verification is carried out. When the absorber has no nested cylindrical structure, there is a large downward fluctuation in its low band, and the average absorption rate in the whole band decreases to 92.21%; when the absorber has no stacked metal rings, there is a significant decrease in the whole band, and the lowest absorption rate decreases to 39.64%, and the average absorption rate is 74.82%; when the absorber is only set with a group of W/Ti rings, the absorber in the whole band absorption rate there is a decrease, the lowest absorption rate is 71.28%, and the average absorption rate is 91.35%. Comparative experimental results show that the designed solar absorber exhibits more efficient and stable absorption in a wide band. Under the optimal parameters of the structure, the absorber can maintain more than 88.51% absorption in the wavelength from 300 to 2 500 nm with an average absorption of 94.34%, and the relative bandwidth of the absorber is 156%. The results show that the absorber has polarization insensitivity and wide-angle absorption characteristics, and its average absorption is 88.81% under the tilted incidence condition of 60°. By comparing with other literature studies, although the average absorption rate of the absorber designed in this paper will be slightly lower than that of the absorber mentioned in the comparison, the large enough relative bandwidth can be more favorable for practical applications, and a comprehensive comparison of the average absorption rate and the relative bandwidth can be concluded that the absorber designed in this paper has an excellent performance. Combined with the electromagnetic field distribution, the analysis shows that the combination of stacked and nested structures has a certain degree of superiority, which can realize the broadband high absorption of solar radiation energy in the main concentration band. The broadband high absorption is mainly attributed to the nested structure of rings and cylinders, the surface plasmon resonance effect between the bottom dielectric layer and the metal layer, and the mutual coupling of multiple resonant modes. The fabrication of such nanodevices has become feasible with the continuous advancement of deposition and lithography technologies. This study provides an important reference for the optimization of the design of ideal absorbers, cloaking devices, and photovoltaic cells, and provides a new research direction for the effective absorption and conversion of solar energy.