The invention provides an oil-gas separator. The oil-gas separator comprises a first shell, a first separator, a second separator and a control valve assembly. The first shell is provided with an oil-gas inlet, a first channel and a second channel, wherein the first channel and the second channel are arranged in a spaced manner. The first separator communicates with the first channel. The second separator communicates with the second channel. The control valve assembly is arranged in the first shell, and the oil-gas inlet selectively communicates with the first channel and/or the second channel through the control valve assembly. The first separator and/or the second separator are/is of a spiral separation structure. By means of the provided technical scheme, the technical problem that anoil-gas separator in the prior art is low in separation efficiency can be solved.