Gas-liquid mixing device

The invention discloses a gas-liquid mixing device which comprises a gas supply device, a liquid supply device, a gas collector with a gas cavity, a mixer with a mixing cavity, a constant pressure valve, a feeding pipe, a discharging pipe and a waste discharging pipe. One end of the feeding pipe is communicated with the gas cavity, the mixing cavity and the gas supply device, the other end of the feeding pipe is communicated with a first connecting pipe, and the first connecting pipe, a first valve body, a second connecting pipe and a waste discharge pipe are communicated; a third connecting pipe, a second valve body, a fourth connecting pipe, a third valve body, a fifth connecting pipe and the gas cavity are communicated, and the liquid supply device is communicated with the fourth connecting pipe; the mixing cavity, a sixth connecting pipe, the constant pressure valve, a seventh connecting pipe, a fourth valve body and the discharging pipe are communicated, and the fourth connecting pipe is communicated wit