Modular multi-stage gas-liquid separation device

The invention belongs to the technical field of gas-liquid separation, and particularly relates to a modular multi-stage gas-liquid separation device. The modular multi-stage gas-liquid separation device comprises a liquid sample injection module, a multi-stage separation module and a gas sample discharging module, wherein the liquid sample injection module is used for forming a water film on a liquid sample, and the formed water film is in contact with a separating film in the liquid sample injection module to perform gas-liquid separation; the multi-stage separation module is arranged between the liquid sample injection module and the gas sample discharging module, and a separation film is arranged in the multi-stage separation module; the pressure of a cavity inside the multi-stage separation module is lower than the pressure of a cavity inside the liquid sample injection module, and the pressure of a cavity inside the gas sample discharging module is lower than the pressure of a cavity inside the multi-st