The present invention discloses a production method of watermelon seeds for lowering internal heat and relieving summer-heat. The method includes the following steps: washing soaked watermelon seeds, shedding powder, placing the watermelon seeds in a boiler, adding clean water, table salt and white granulated sugar into the boiler, cooking the mixture, continually heating the boiler until the mixture is boiled and performing heat preservation, cooling the mixture, adding cogongrass rhizome, honeysuckle, chrysanthemum, selfheal, agastache rugosus, folia bambosae, semen cassiae and green tea into the mixture, continually heating the boiler and performing heat preservation, cooling the mixture, adding perilla leaves, haws, dried orange peels, radix ophiopogonis and mint leaves, continually heating the boiler and performing heat preservation, cooling the mixture to room temperature, adding fennel, cassia cinnamon, lemon grass, hypocrimson manna lichen carpophore, marsh orchis herb, cushaw stems and dried orange peels, continually heating the boiler and performing heat preservation, and removing and draining the mixture to obtain material A; dehydrating the watermelon seeds followed by an initially frying; spreading and airing the watermelon seeds followed by a additional frying; spreading and airing the watermelon seeds followed by a final frying, and spreading and airing the watermelon seeds to obtain the watermelon seeds for lowering internal heat and relieving summer-heat.