The invention relates to a perfluoroisobutyronitrile sub-packaging device. The perfluoroisobutyronitrile sub-packaging device comprises a weighing system, a two-position three-way solenoid valve, a sub-packaging main pipeline and sub-packaging branch pipelines. An original perfluoroisobutyronitrile steel bottle is placed on the weighing system and provided with a gaseous port and a liquid port. Afirst connector, second connector and third connector of the two-position three-way solenoid valve are connected with the gaseous port and liquid port of the original perfluoroisobutyronitrile steel bottle and an inlet of the sub-packaging main pipeline correspondingly. Inlets of all the sub-packaging branch pipelines are connected with the sub-packaging main pipeline. Each sub-packaging branch pipeline is provided with a sub-packaging solenoid valve. Outlets of all the sub-packaging branch pipelines are respectively connected with one sub-packaging perfluoroisobutyronitrile steel bottle. Theperfluoroisobutyronitrile sub-packaging device has the advantages of being scientific in principle, simple in structure and convenient to operate, avoiding the gaseous mixing of impurities in the process of perfluoroisobutyronitrile sub-packaging, reducing the retention of liquid perfluoroisobutyronitrile in pipelines as much as possible and reducing the waste of perfluoroisobutyronitrile and theuse cost.