This paper reports low-energy electron scattering with \mathrmC_4^- anions by using the ab initio R -matrix method in the single state close-coupling (CC) model and the fixed-nuclei approximation. We predict the elastic integral scattering cross sections (ICSs) of four conformers of \mathrmC_4^- ions in an energy range of 0 < E ≤12 eV and discuss the effects of configuration changes on resonance position and width. Additionally, the theoretical results and experimental data are compared and analyzed. The results indicate that the 8.8 eV resonance peak observed in experiment is mainly derived from the \Sigma _\mathrmu^+ and \Sigma _\mathrmu^- resonances of the conformer A and the A₂ resonance of the conformer C. The scattering cross-section reveals that the conformer A has five resonant states, and the conformer B has three resonances, while C and D each have four resonances. Finally, we use the Boltzmann distribution to calculate the populations of different conformers at different temperatures, and simulate the low-energy electron elastic integrated scattering cross-section at room temperature, which is in good agreement with available experimental results. We also find a shape resonance with a width of 0.20 eV at 3.3 eV in our total cross sections, which is not detected in the existing experimental results. This provides new opportunities for measurement.