the gas density relay body comprises: a housing, and a pressure detection element, a temperature compensation element, a signal generator, and a signal action mechanism which are arranged in the housing;

the driving contact action mechanism is configured to trigger the signal generator to make the gas density relay body generate an alarm and/or locking contact signal action;

the intelligent control unit is respectively connected to the simulation reference signal unit, the simulation check signal unit, and the driving contact action mechanism, and is configured to receive data and/or signals collected by the simulation reference signal unit and the simulation check signal unit, control the driving contact action mechanism, and monitor the occurrence of a contact signal action of the gas density relay body;

the simulation reference signal unit is configured to monitor a pressure change value or a temperature change value or a gas density change value in the gas density relay body; the simulation check signal unit is configured to detect one or more of the deformation quantity of a part subjected to deformation and the displacement quantity of a part subjected to displacement due to pressure change or temperature change or gas density change in the gas density relay body; the intelligent control unit determines whether a difference value between the deformation quantity of the part subjected to deformation and/or the displacement quantity of the part subjected to displacement when pressure or temperature or gas density in the gas density relay body changes and a preset standard value, and a corresponding preset standard value is within a preset threshold; or,

the simulation reference signal unit is configured to collect a pressure value or a temperature value or a gas density value in the gas density relay body; the simulation check signal unit is configured to detect one or more of the deformation state of a part subjected to deformation or the position of a part subjected to displacement due to pressure change or temperature change or gas density change in the gas density relay body; the intelligent control unit determines whether a difference value between the deformation state of the part subjected to deformation and/or the position of the part subjected to displacement corresponding to a set pressure value or temperature value or gas density value in the gas density relay body and a preset standard value, and a preset standard value corresponding thereto is within a preset threshold; or,

the simulation check signal unit is configured to output a simulation check signal when any one or more of pressure, temperature and gas density in the gas density relay body changes; the simulation reference signal unit is configured to monitor one or more of a pressure value, a temperature value and a gas density value in the gas density relay body when the simulation check signal is output; and the intelligent control unit determines whether a difference value between the pressure value and/or the temperature value and/or the gas density value and a preset standard value, and a preset standard value corresponding thereto is within a preset threshold.