The nitrogen flow rate of this system adopts a vortex flowmeter with signal remote transmission, which can display the flow rate on the touch screen and set upper and lower limit alarm values for the flow rate. If the flow rate is too low or too high, an alarm can be displayed on the touch screen. The pressure of nitrogen and hydrogen can be displayed on the touch screen, and the high and low pressure alarm values can be set. The hydrogen concentration instrument signal is uploaded to the touch screen, which can display the hydrogen content and set high and low alarm values. When the customer sets the required hydrogen content value on the human-machine interface touch screen, the hydrogen flow rate will change with the change of nitrogen flow rate or total mixture flow rate, always ensuring the set hydrogen content value.