In this paper, we propose an RLC equivalent circuit model theory which can accurately predict the spectral response and resonance characteristics of metamaterial absorption structures, extend its design, and characterize the parameters of the model in detail. By employing this model, we conducted computations to characterize the response wavelength and bandwidth of variously sized metamaterial absorbers. A comparative analysis with Finite Difference Time Domain (FDTD) simulations demonstrated a remarkable level of consistency in the results. The designed absorbers were fabricated using micro-nano fabrication processes, and was experimentally tested demonstrate absorption rates exceeding 90% at a wavelength of 9.28 μm. The predicted results are then compared with test results. The comparison reveals good consistency in two aspects of the resonance responses, thereby confirming the rationality and accuracy of this model.