Provided is a double-chain siRNA molecule targeting a microphthalmia-associated transcription factor MITF coding gene. A sense strand of the siRNA molecule has a sequence of SEQ ID NO: 3 and an anti-sense strand has a sequence of SEQ ID NO: 4, and the anti-sense strand specifically binds to mRNA of the MITF coding gene, to degrade the mRNA, thereby reducing the synthesis of melanin. Further provided is an application of the siRNA molecule in freckle whitening cosmetics or the preparation of medicines for treatment of diseases related to melanin gene.
