The invention relates to a cultivating method of dragon fruits. The cultivating method includes S1, choosing sandy soil lands with PH (potential of hydrogen) value 6.5-8; S2, growing seedlings, to be specific, performing transplanting when height of the seedlings reaches 5cm or above; S3, performing transplanting, to be specific, planting supports on the land where the dragon fruits are planted, 3-5 dragon fruit seedlings are transplanted around each support with planting density of 300-350/mu; S4, performing daily management including the steps of 1, uniformly fertilizing before flowering, and adding potash fertilizer and magnesium fertilizer during flowering period and fruit setting period; 2, keeping soil wet; 3, covering the peripheries of roots with dry glasses; 4, pruning branches; S5, performing insect disease prevention. The cultivating method has the advantages that the dragon fruits are natural and pollution-free, investment cost is low, and economic and practical effect is achieved.