To facilitate engineering applications and quantitatively describe the damage level of concrete components, referring to the constitutive model of concrete mentioned in Appendix C of the current Chinese standard “Code for Design of Concrete Structures” GB/T 50010—2010, this paper proposes a damage assessment method for concrete components based on material damage. That is, the damage level of the component is defined according to the values of the damage evolution parameter. It is specified that when the damage evolution parameter dc(t) is less than the damage evolution parameter dc(t),r corresponding to the peak strain of concrete εc(t),r, the concrete component is in a non-damaged state (Level L1); when the damage evolution parameter dc(t) is greater than the damage evolution parameter dc(t)u corresponding to the strain of concrete εc(t)u, the concrete component is in a severely damaged state (Level L6); when the damage evolution parameter dc(t) is between the two values, the damage state of the concrete component (Levels L2 to L5) is evaluated by the linear interpolation method. To verify the rationality of this method, a refined model of 18 beams and 2 columns was established using the ABAQUS software, and numerical analysis were conducted. The simulation results show a good agreement with the test results. According to the damage assessment method proposed in this paper, most of the beam components under the peak load and the column components under the yield load are in a severely damaged state (Level L6). However, when using the damage assessment method based on the compressive strain of concrete as mentioned in the “Standard for Performance-Based Seismic Design of Building Structures” T/CECA 20024—2022, most of the components are in a moderately damaged state (Level L4), while a minor portion of the components are in a relatively severe damaged state (Level L5). From a macroscopic perspective, the damage assessment method for concrete components based on material damage proposed in this paper is more consistent with the actual expectations for evaluating the damage of concrete components and has a certain reference value.