Double-tower nitrogen making system

The invention relates to the technical field of nitrogen making equipment, in particular to a double-tower nitrogen making system which comprises a precooling module, a first purification module, a heat exchanger, a high-pressure nitrogen tower, a first subcooler, a first condensation evaporator, a low-pressure nitrogen tower, a second condensation evaporator, a high-purity oxygen tower and a first reboiler. By arranging the high-purity oxygen tower communicated with the low-pressure nitrogen tower, the whole system can utilize air to produce nitrogen products, and the high-purity oxygen tower can also utilize liquid and gas in the low-pressure nitrogen tower to produce high-purity oxygen products, namely, the whole system can utilize air to produce the nitrogen products and the high-purity oxygen products at the same time; air serving as a raw material is fully utilized, and the input-output ratio of the raw material is increased.