The invention discloses high-temperature direct-injection disperse ink as well as a preparation method and an application thereof. The ink is prepared from the following raw materials in parts by weight: 15-60 parts of high-temperature disperse dye, 0.3-20 parts of dispersant, 30-60 parts of organic solvent, 10-50 parts of water, 0.5-10 parts of surfactant, 0.05-0.2 part of preservative and 0.05-0.2 part of defoamer. The preparation method comprises the steps of evenly mixing the high-temperature disperse dye, the dispersant, the organic solvent and water together, adding zirconium beads for grinding and dispersing, and then adding the rest organic solvent, water, the surfactant, the preservative and the defoamer to the mixture, mixing evenly, and filtering to obtain the filtrate. The ink is applied to a novel industrial digital textile printing machine and in particular to a textile printing machine with a precision work 508GS nozzle; the ink can be directly injected for printing by using the printing machine, and therefore, the utilization rate of the ink is increased, the cost is reduced and the environmental pollution is reduced; the ink can be dyed quickly at high temperature without transfer printing, and thus has the advantages of short dyeing time, firm dyeing and the like.