The invention relates to a dyeing method of an elastic patterned gray blended knitted fabric. The method comprises the following steps of (1) pretreatment, wherein oil removal and gray cloth setting are carried out on an elastic gray cloth of the elastic patterned gray blended knitted fabric; (2) dyeing, wherein the elastic gray cloth is put into a dyeing vat, and water, a dispersant, a part of acolor homogenizing agent and an acid releasing agent are added for dyeing; (3) post-treatment, wherein a color fixing agent is added for color fixing after the gray cloth is washed with water. According to the method, a two-step approach based on one bath is adopted, the pretreatment of oil removal and gray cloth setting is carried out, and then the dispersant, the color homogenizing agent and theacid releasing agent are adopted, so that oligomer agglomeration is prevented, it is ensured that a stable acidic environment is formed in the dyeing process, and a great coloring effect is realized;finally, the color stability of the dyed gray cloth is ensured through the post-treatment of washing and color fixing; the color fastness is high, a dyeing and finishing process is optimized, the dyeing process is simplified, the working time is shortened, the energy consumption is reduced, the color difference of fabrics after dyeing and finishing processing is avoided, and the finished productefficiency is obviously improved.