The invention relates to a dryer with nitrogen as a heat-transfer medium. The dryer comprises a nitrogen bottle, a heat collector and a drying chamber. Sealing gas channels are arranged between the nitrogen bottle and an air inlet of the heat collector, between an air outlet of the heat collector and an air inlet of the drying chamber as well as between an air inlet of the drying chamber and the nitrogen bottle. Valves are arranged on the sealing gas channels. The dryer with the nitrogen as the heat-transfer medium is combined with the unique advantages of solar energy resources in Sinkiang; meanwhile, the nitrogen serves as the heat-transfer medium to heat fruits in the closed space; it is avoided that when air is used for heating, due to oxidation on the fruits by oxygen in air, color and luster of the fruits are changed and the quality of the fruits is reduced; the solar energy drying technology and the nitrogen serving as the heating medium are jointly applied to the fruit drying field, so that the problems caused by natural airing and drying are solved, and the quality of the fruits is improved.