The invention provides a gas density relay based on ubiquitous power Internet of Things applications. The gas density relay comprises a shell, and a base, a pressure detector, a temperature compensation element and at least one signal generator which are arranged in the shell, and further comprises a comparison pressure value output signal or a comparison density value output signal; the comparison pressure value output signal is monitored by the pressure detector on the gas pressure, and is output through a comparison annunciator; the comparison density value output signal is obtained from monitoring the gas density by the pressure detector and the temperature compensation element, and is output by the comparison annunciator. Compared with the prior art, the comparison pressure value output signal or the comparison density value output signal are added, so mutual verification of a mechanical part and an electronic part of the gas density relay can be achieved in a density monitoring device or system, the working efficiency is improved, the operation and maintenance cost is reduced, and safe operation of the power grid is guaranteed.