A refrigerant pipeline gas-liquid separator in front of a compressor comprises a horizontal drum, a front cover, a rear cover, an air outlet pipe and a liquid observing device. The horizontal drum isa horizontally-arranged circular iron drum. An inlet pipe is a straight pipe with an inclined cut. The front cover is formed by welding an arc-shaped spherical surface plate with a cylindrical shell.The rear cover is a circular plate. The air outlet pipe is a bent pipe of which the two ends use straight pipe bodies and the middle is in smooth transition. A liquid level meter is used as the liquidobserving device. An observation pipe is made from transparent PVC, sealed through a nitrile rubber washer and tightened and fixed through a threaded cap. According to the gas-liquid separator, the inlet pipe is arranged for enabling a refrigerant entering the horizontal barrel to keep away from the air outlet pipe as far as possible, the gas liquid separation distance is increased, liquid and gas in the refrigerant are dissipated more rapidly through the inlet pipe with the inclined cut at the tail end, and thus the gas liquid separation speed is increased.