The utility model discloses an automatic oil metering and gas testing device for single well, which comprises a separating pot main body, wherein, both sides of the upper part of the separating pot main body are respectively provided with mixing fluid inlet valves, exhaust valves and gas flow meters, and the bottom of the separating pot main body is provided with a liquid discharging valve. The lower side part of the separating pot is provided with a differential pressure transmitter, and the high pressure chamber and the low pressure chamber of the differential pressure transmitter are communicated with the separating pot by a metal guide pipe, and a guide pipe with a liquid level meter is horizontally arranged above the differential pressure transmitter and is respectively connected with the separating pot and a guide pipe of the low pressure chamber of the differential pressure transmitter which respectively outputs signals to a computer. The utility model has the characteristics of speediness and exactness, and can automatically meter the oil production, the gas production, the liquid production and the moisture percentage of a single-mouth well.