Severe effluent pollution and chemical damage to protein fibers generated from conventional aqueousdyeing process have stimulated interest in exploiting sustainable dyeing of wool. Herein, an ethanol(EtOH)-carbon tetrachloride (CCl4)-water (H2O) ternary solvent system was used as the dyeing mediumto protect wool fibers from being damaged in the dyeing process. The wool fibers were firstly pretreatedin an aqueous acid solution, followed by dyeing in the EtOH-CCl4-H2O (45:50:5) ternary solvent systemwith reactive dyes. The results indicated that the acid pretreatment solution could be reused for severaltimes, the samples dyed in the EtOH-CCl4-H2O mixture with the investigated dyes showed higher K/S valuescompared to the conventional approach, implying the increased dye utilization and decreased effluentsdischarge were realized. Furthermore, acceptable permeability, good colorfastness, and satisfactoryleveling properties of the dyed samples were achieved using the developed method. Additionally, thesolvent-assisted dyed samples showed improved mechanical properties compared with the conventionallydyed samples. The dyeing mechanisms of wool fibers in the EtOH-CCl4-H2O mixture were illustratedin detail. The proposed dyeing technology consumes fewer energy, freshwater, and chemicals comparedwith the conventional wool dyeing method. Future work will principally concentrate on the reuse of thedye-contaminated EtOH-CCl4-H2O mixture.