A dewar structure applied to a saturated core type superconducting current limiter cooling system comprises a low-temperature dewar and a refrigerating dewar, wherein the low-temperature dewar and the refrigerating dewar are arranged in two places and communicated with each other; equipment (including a refrigerator) needed for normal operation of a low-temperature system is mounted on the refrigerating dewar; low-temperature equipment (including a magnet or a coil) is arranged in the low-temperature dewar; the space between the low-temperature dewar and the refrigerating dewar at the two placed is at least large enough to reduce the interference between the low-temperature dewar and the refrigerating dewar to a point conforming to the requirement. The low-temperature dewar and the refrigerating dewar are communicated with each other in the following ways: when applied to a closed system, the two dewars are connected through a top gas pipe and a bottom liquid pipe respectively so that the gas pressures as well as the liquid levels of the two dewars are kept consistent; when applied to an open system, the two dewars are connected only through the bottom liquid pipe. The dewar structure can operate safely and reliably and has no interference with electrical equipment even in a high magnetic field, limited volume and high electric field environment.