The invention provides a metering separation skid-mounted device with a gas amount adjusting-distribution function. The metering separation skid-mounted device comprises a natural gas inlet, a liquid discharging outlet, a vent gas outlet and a separator. The natural gas inlet communicates with an inlet of the upper end of the separator through a pipeline. A flow meter and a first adjusting valve are sequentially arranged on the pipeline between the natural gas inlet and the separator. An outlet of the upper end of the separator communicates with the vent gas outlet through a pipeline. The outlet of the lower end of the separator communicates with the liquid discharging outlet through a pipeline provided with a first pneumatic ball valve. An eighth ball valve, a second pneumatic ball valve, a second throttling valve and a ninth ball valve are sequentially arranged between the first pneumatic ball valve and the liquid discharging outlet. A liquid level metering device is arranged on the separator. According to the liquid level measured by the liquid level metering device, the corresponding pneumatic ball valve and the corresponding adjusting valve are adjusted so as to control liquid discharging effectively. When the flow of gas in the flow meter is changed, accordingly the opening degree of the corresponding adjusting valve is changed.