The invention relates to a normal-pressure
dyeing method of a meta-
aramid yarn, belonging to the technical field of
textile printing and
dyeing. The method comprises the following steps: coarsening the meta-
aramid yarn, wherein the coarsening process is as follows: acid or alkali is 10-20 g / L, a penetrant is no more than 2 g / L, the bath ratio is 1:10-20, the temperature is 90-100 DEG C, and the time is 20-30 min; then, washing with water to obtain the meta-
aramid yarn with a coarsened
fiber surface; activating the meta-aramid yarn with coarsened
fiber surface, wherein the activating process of the meta-aramid yarn with a coarsened
fiber surface is as follows: a cation modifier is 10-20 g / L, the bath ratio is 1:20-30, the temperature is 60-90 DEG C, and the time is 30-40 min; and finally,
dyeing the meta-aramid yarn, i.e. dyeing the meta-aramid yarn to be dyed under the normal pressure to obtain a
colored meta-aramid yarn. The invention is beneficial to saving energy, avoids damage to fibers, has no stringent requirements on the dyeing device and facilitates the operation. Besides, the invention realizes that the fabric subjected to subsequent
processing can be provided with required patterns in accordance with the weaving process.