The invention discloses a method for dyeing chrome tanned crust leather by utilizing an active dyestuff. The method comprises the following steps: retanning water-returned wet blue leather by a chrome tanning agent and an aldehyde tanning agent; retanning by adopting amphoteric acrylic polymer resin containing rich primary amino groups and carboxylate radical; dyeing by adopting the active dyestuff. By retanning through the chrome tanning agent, the aldehyde tanning agent and the amphoteric acrylic polymer resin, the content of chrome in the wet blue leather is increased and the alkali resistance of the crust leather is improved; meanwhile, more free amino groups are introduced into chrome tanned collagen fibers and active sites where the crust leather is reacted with the active dyestuff are increased; a retanning agent is matched and selected, so that the dyeing pH (Potential of Hydrogen) and temperature of the active dyestuff and the tolerable temperature and pH of the crust leather are more fitted, and the difficulty that the active dyestuff is difficultly used for dyeing the crust leather is overcome; the dyed crust leather has relatively high dry and wet rubbing fastness and fastness to washing.