The invention relates to a miniature gas and liquid separator, which comprises a columnar barrel (1), a gas and liquid buffering barrel (2) and a crude oil input pipe (3). The columnar barrel (1) is provided with a gas outlet pipe (11) and a liquid outlet pipe (12), the upper end and the lower end of the gas and liquid buffering barrel (2) are a gas-phase outlet end (21) and a liquid-phase outlet end (22) respectively, the gas-phase outlet end (21) and the liquid-phase outlet end (22) are respectively tangentially jointed with a gas-phase inlet (14) and a liquid-phase inlet (15) on a side wall of the columnar barrel (1), and the crude oil input pipe (3) is obliquely downward relative to the gas and liquid buffering barrel (2), and is tangentially jointed with the middle of a side wall of the gas and liquid buffering barrel (2). The miniature gas and liquid separator is high-efficiency and compact in design, functions of a separation area and a buffering area are clearly distinguished, and an effect of reducing the integral volume of the separator can be achieved. In addition, the miniature gas and liquid separator is suitable for being mounted on a vehicle, and can be conveniently used at places with limited spaces, such as wellheads, ocean platforms and the like, simultaneously, material cost is also saved, and safety is higher.