The invention relates to the field of dyes, and particularly discloses a low-photosensitive high-fastness reactive gray dye composition and a preparation method and a
dyeing method thereof, and the dye composition comprises the following raw materials: 28-35 wt% of reactive red, 15-25 wt% of reactive blue 220, 25-40 wt% of reactive blue 222, and the balance of a
solvent. The preparation method of the dye composition comprises the following steps: mixing the reactive red, the reactive blue 222 and the reactive blue 220 in proportion, performing jet milling, adding a
solvent, and performing
spray drying to obtain the powdery dye. The
dyeing method comprises the following steps: immersing a fabric into the gray dye composition according to a water bath ratio of 1: (8-12) at 50-70 DEG C, adding
anhydrous sodium sulphate, carrying out heat preservation for 25-35 minutes, adding
sodium carbonate, carrying out heat preservation for 50-65 minutes,
fishing out the fabric, and carrying out
water washing, soaping and
water washing to obtain the dyed fabric. The obtained dyed fabric is low in
light sensitivity and high in fastness.