With the diversification of types and service environment of power grid facilities, as well as the continuous development of underground substations, underground cable channels and underground energy storage power stations, the adaptability of safety control and emergency rescue mechanisms established by manual methods in the past is getting worse and worse. Intelligent perception of power grid operation status in limited space and improvement of signal transmission capability are effective ways to achieve reliable operation in limited space. This paper mainly carries out breathing monitoring technology suitable for all kinds of limited space operators, and realizes the functions of accurate perception and intelligent warning of limited space operation status of power grid operators, and all-weather and realtime monitoring of operators.