PH3/H2 online mixing system

The utility model discloses a PH3/H2 online mixing system. The system mainly comprises a PH3 supply device, an H2 supply device, a mixed gas pipeline, a mixed gas buffer storage device and an He purging device, the He purging device is connected with the PH3 supply device; the tail end of the PH3 supply device and the tail end of the H2 supply device are connected to one end of the gas mixing pipeline; the other end of the gas mixing pipeline is connected with a gas mixing buffer storage device; the utility model relates to a PH3/H2 online mixing system. The PH3 supply device and the H2 supply device are used for supplying gas and mixing; conveying is performed through a gas mixing pipeline; the mixed gas is accumulated in the mixed gas buffer storage device; therefore, the PH3/H2 mixed gas can be taken and used at any time, the purchasing procedure of the mixed gas is simplified, the purchasing period of the mixed gas is shortened, the purchasing cost and the logistics cost of the mixed gas are reduced, in a