The invention discloses a composition and shower gel for skin whitening and a preparation method of the composition and belongs to the field of daily chemical product. The composition comprises, by weight, 10-40 parts of ginseng extract, 5-10 parts of Angelica dahurica extract, 8-20 parts of Melothria heterophylla extract, 10-20 parts of Pharbitis seed extract, 5-15 parts of white poria extract, 10-20 parts of Bletilla extract, 5-10 parts of stiff silkworm extract, 5-10 parts of pearl powder, and 10-20 parts of milk essence. The composition is functional in whitening and moisturizing, removing freckle and wind and resisting oxidization and is significant to the preparation of products for skin whitening. In addition, the composition has a simple formula, various ingredients are both medicinal and dietary, and the composition is safer and more reliable.