The utility model discloses a dual-ring high-efficiency desulfurization absorbing tower and a desulfurization system using the same. The dual-ring high-efficiency desulfurization absorbing tower disclosed by the utility model comprises an outer desulfurization tower and an inner desulfurization tower; a smoke outlet is formed at the upper part of the outer desulfurization tower; spray layers are arranged at the middle part of the outer desulfurization tower; a slurry pool is arranged at the lower part of the outer desulfurization tower; a smoke inlet is formed at the upper part of the inner desulfurization tower; spray layers are arranged at the middle part of the inner desulfurization tower; the inner desulfurization tower is sleeved inside the outer desulfurization tower; and the bottom of the inner desulfurization tower is located below the spray layer of the outer desulfurization tower and communicated with the outer desulfurization tower. The desulfurization system disclosed by the utility model, comprises a slurry circulating pump, an oxidation air pipe, an oxidation fan, a slurry draining pump and the dual-ring high-efficiency desulfurization absorbing tower. According to the utility model, the outer desulfurization tower and the inner desulfurization tower with different diameters are sleeved together to be connected in series, therefore, the desulfurization efficiency is greatly improved, and the construction and operation costs are reduced.