The optimal performance of the solar-driven thermodynamics cycle system consisting of a solar collector and a four-temperature-level absorption refrigerator is investigated, based on the linear heat-loss model of a solar collector and the irreversible cycle model of a four-temperature-level absorption refrigerator. A fundamental optimum relation is derived, from which the optimum operating temperature of the solar collector, the maximum overall coefficient of performance and the corresponding coefficient of performance of the four-temperature-level refrigerator are determined. It is proven that the total thermal conductance of the heat exchangers must be divided optimally between the four heat exchangers. The effects of the cycle parameters on the optimum operating temperature of the solar collector and the performance of the system are discussed by detailed numerical examples. The results obtained can describe the optimal performance of solar-driven four-temperature-level refrigerator affected simultaneously by the internal and external irreversibilities.