The invention relates to a preparation method of a special biological astaxanthin nutrient solution applied to dendrobium officinale kimura ex migo. The formula of the special biological astaxanthin nutrient solution comprises the following components in percentage by weight: 2.7-3.7% of valine, 2.8-3.8% of sodium molybdate, 2.9-3.7% of lysozyme, 3.2-4% of a turnera diffusa extract, 3.1-3.9% of menadione dimethylpyrimidinol bisulfite, 2.8-3.7% of bacillus lentus, 0.1-1.1% of manganese carbonate, 1.5-2.5% of a snake gall extract, 0.3-1.3% of nervilia fordii, 1.3-2.3% of a sophora alopecuroidesextract, 0.6-1.6% of daphniphyllum calycinum, 1.1-2.1% of an artichoke extract, 2.6-3.6% of bifidobacterium longum, 1.8-2.8% of ilex rotunda thunb, 2.1-3.1% of galactooligosaccharide, 2.7-3.7% of a pithecellobium clypearia extract, 1.9-2.9% of olive oil, 1.7-2.7% of highland barley flour, 0.6-1.6% of probiotics, 0.3-1.3% of astaxanthin and 44.6-63.9% of water. The special biological astaxanthin nutrient solution is capable of effectively providing nutrients needed by the growth of the dendrobium officinale kimura ex migo, accelerating the growth of seedlings, enabling the leaf surfaces to be glossy dark green and thick, controlling spindling of young shoots, accelerating dendrobium officinale kimura ex migo to be thick with leaves and deep-rooted, enhancing stress resistance and immunity of the dendrobium officinale kimura ex migo, improving soil activity, enabling dendrobium officinale kimura ex migo to be strong and enhancing the ornamental value of dendrobium officinale kimura ex migo.