A gas-liquid separator, comprising a housing with an inner cavity and a first outlet pipe, wherein, the first outlet pipe extends in an inner cavity of the gas-liquid separator, and passes through a side wall of the housing to reach an outside of the housing; the gas-liquid separator further comprises a fixing member; the fixing member is disposed in the inner cavity of the gas-liquid separator; and the fixing member is fixedly connected to the housing and the first outlet pipe; the first outlet pipe passes through a first position of the side wall of the housing to reach the outside of the housing; the first outlet pipe is connected to the fixing member at a second position; the first outlet pipe has an inner extension section extending in a vertical direction and an outer connection section extending in a horizontal direction; the inner extension section and the outer connection section are connected by a bent section; the inner extension section and the bent section are disposed in the inner cavity of the gas-liquid separator; the outer connection section passes through the side wall of the housing to reach the outside of the housing; characterised in that: the gas-liquid separator comprises a liquid suction pipe, wherein one end of the liquid section pipe extends to a bottom of the inner cavity of the gas-liquid separator, and another end of the liquid suction pipe is connected to the outer connection section of the first outlet pipe; and in that in the vertical direction, the first position is distanced from the second position by a first distance; an end of the first outlet pipe extending to a top portion of the inner cavity of the gas-liquid separator is distanced from the first position by a second distance; and a ratio (H3/H2) of the first distance to the second distance is between 0.3 to 0.7. the first outlet pipe extends in an inner cavity of the gas-liquid separator, and passes through a side wall of the housing to reach an outside of the housing; the gas-liquid separator further comprises a fixing member; the fixing member is disposed in the inner cavity of the gas-liquid separator; and the fixing member is fixedly connected to the housing and the first outlet pipe; the first outlet pipe passes through a first position of the side wall of the housing to reach the outside of the housing; the first outlet pipe is connected to the fixing member at a second position; the first outlet pipe has an inner extension section extending in a vertical direction and an outer connection section extending in a horizontal direction; the inner extension section and the outer connection section are connected by a bent section; the inner extension section and the bent section are disposed in the inner cavity of the gas-liquid separator; the outer connection section passes through the side wall of the housing to reach the outside of the housing; characterised in that: the gas-liquid separator comprises a liquid suction pipe, wherein one end of the liquid section pipe extends to a bottom of the inner cavity of the gas-liquid separator, and another end of the liquid suction pipe is connected to the outer connection section of the first outlet pipe; and in that in the vertical direction, the first position is distanced from the second position by a first distance; an end of the first outlet pipe extending to a top portion of the inner cavity of the gas-liquid separator is distanced from the first position by a second distance; and a ratio (H3/H2) of the first distance to the second distance is between 0.3 to 0.7.