The invention discloses a vacuum low-temperature radiosensitivity electromagnetic compatibility experimentation system which comprises an antenna, an electronics system, a laboratory power supply, a monitoring system and a testing device. The testing device comprises a vacuum tank, a vacuum pump and temperature control equipment. The vacuum tank comprises a stainless steel tank body and a wave-transparent glass window which is arranged at one end of the stainless steel tank body. The vacuum pump is communicated with the vacuum tank and carries out vacuumizing on the vacuum tank. The temperature control equipment is communicated with the vacuum tank and carries out low temperature or temperature rising control over the vacuum tank. A detector is arranged in the testing device and is electrically connected with the electronics system. The laboratory power supply provides a power source for the electronics system. The monitoring system is electrically connected with the electronics system. The antenna corresponds to the testing device and is close to the wave-transparent glass window. The vacuum tank is used in the testing device, so that the detector is contained, the vacuum tank is subjected to vacuumizing through the vacuum pump, the inner portion of the vacuum tank is controlled to be in a low-temperature environment through the temperature control equipment, and accordingly the detector is in a vacuum low-temperature testing environment.