The invention provides a system and a process for condensing and recovering a nitrogen tetroxide waste gas resource, which belong to the field of waste gas treatment. The system comprises a condensingheat exchanger, a gas-liquid separator, an electric control valve, a condensate collecting tank, a low-temperature water chilling unit, and an ethylene glycol water solution buffer and expansion tank. A pipeline of waste gas containing nitrogen tetroxide steam enters the condensing heat exchanger; a gas-liquid mixture outlet pipeline of the condensing heat exchanger is connected with the gas-liquid separator; the gas-liquid separator is connected with the condensate collecting tank through a gas communicating pipe. In the system, the low-temperature water chilling unit provides a cooling capacity for cooling the temperature of an ethylene glycol water solution to the operating temperature, the ethylene glycol water solution cools the waste gas containing the nitrogen tetroxide steam through heat exchange so as to achieve a supersaturated state, and nitrogen tetroxide is recovered through gas-liquid separation. In the process, the ethylene glycol water solution is not only an intermediate heat transfer working medium but also a cold storage working medium, so that the system is ensured to operate stably.