The invention discloses a wool bright red reactive dye and a preparation method thereof. The wool bright yellow reactive dye takes 2,4-diaminobenzenesulphonate sodium, 1-Naphthol-5-sulfonic acid and 2,3-dibromopropionyl chloride as main raw materials, and is prepared through condensation, diazotization, coupling, color tone adjustment, strength adjustment, drying and packaging. The prepared wool bright red reactive dye has the advantages of high reactivity, excellent solubility, fresh and beautiful color tone, good color fastness to light, and high absorbability and degree of fixation. The preparation method adopts front blend technology and a primary pulp spray method after film treatment, can put an end to generation of dust, and greatly promotes environmental protection.