Steel made low pressure wet gas holder is a low pressure gas storage equipment. The security of the steel made low pressure wet gas holder used in the petroleum chemical industry, municipal engineering was researched from the aspects, the operation pressure of the wet gas holder, the design for filling water and antifreeze, and the safety instrument design for tank level measuring and water level detection, temperature and pressure detection. When steel made low pressure wet gas holder is constructed in the north of China, antifreezing should be considered, instead it didn't need to be considered in the south. Therefore, designers should consider the antifreezing of the gas holder when they ensure its selection scheme.