The invention provides hot-coated fast-setting cake jam. The jam is prepared from carrageenan, konjac gum, gellan gum, pectin, white sugar, trehalose, glucose powder, sorbitol, glycerin, malt syrup, calcium lactate, potassium chloride, edible salt, hydroxypropyl distarch phosphate, concentrated juice, potassium sorbate, essence for food, citric acid, malic acid and water. The invention further provides a preparation method; the hot-coated fast-setting cake jam is prepared by mixing a prepared emulsifying colloid system and viscous mixed liquor under the condition of the temperature being 85 DEG C to 90 DEG C, and adding a mixture C solution, the essence for food and a premix D. The preparation method provided by the invention is simple; the prepared hot-coated quick-setting cake jam is directly coated on the surface of cake under the condition of the temperature being 85 DEG C; the setting time is short; the setting is fast and nutrition is locked; the appearance is crystal clear aftersetting, the taste is sweet and sour, and the melting performance in the mouth is good.