The solar power plant is a large-scale photovoltaic (PV) system aimed to generate solar power for the electricity grid. It includes PV arrays (PVAs), cables, and other electrical accessories. Moreover, the solar power plant builder must consider various parameters and design regulations. The cable routing problem (CRP) is critical in large-scale solar power plant design. The objective of our CRP is to minimize the installation cost of the cable by determining the partition of the photovoltaic array and the cable routing. In this study, we use the quantum computer to solve the CRP, an NP-hard integer linear programming (ILP) problem, and show its advantages over classic computers. We transfer the ILP CRP into the quadratic unconstrained binary optimization (QUBO) model and solve it by the advanced quantum annealer. Finally, we analyze the computational results and discuss the advantages of our approach to solving the CRP.