The invention discloses micro-carbon plant anthocyanin for promoting early coloring of fruit and fullness of fruit and a preparing method and application thereof. The micro-carbon plant anthocyanin is prepared from, by mass, 30-50% of plant anthocyanin with particle size of 80-150 microns, 20-30% of micro-carbon (shortened form of water-soluble lower molecular carbohydrate) with particle size of 100 microns and 20-50% of amino acid. The preparing method comprises the steps of preparing plant stems and leaves rich in anthocyanin, humic acid and amino acid according to grain standard; conducting biodegradation on the raw materials, wherein humic acid is added to active yeast spawn in proportion to be fermented and degraded into micro-carbon , and the plant stems and leaves rich in anthocyanin are added to yeast spawn in proportion to be fermented and degraded so that plant anthocyanin can be extracted; conducting semi-finished product potting; conducting blending, mixing, inspection and finished product generation. By spraying 100-500 times diluent onto the surfaces of leaves and fruits of grapes and strawberries in the developmental phase and using 10-50 kg for each mu in the whole bearing period, coloring can be achieved 5-15 days earlier, and fruits taste sweet, are full and have high quality.