The invention discloses a horizontal magnetic suspension type hydraulic centrifugal separating device. The device comprises a cylindrical housing, an inner barrel body, blades, a hollow spiral conveyor and a fluid pipeline, wherein a first magnet is arranged on the inner wall of the cylindrical housing; a sludge discharging port and a clean liquid draining port are correspondingly formed in the front end and the rear end in the axial direction of the housing; a second magnet is arranged on the outer wall of the inner barrel body, and a magnetic pole of the second magnet is in the direction opposite to that of the first magnet, and thus the inner barrel can be suspended in the housing through the magnetism; the inner barrel body and the housing are coaxially arranged; a sludge outlet and aclear liquid outlet are correspondingly formed in the front end and the rear end in the axial direction of the inner barrel body; the blades are arranged at the tail end of the inner barrel body and are used for driving the inner barrel body to rotate around own axis through driving force. The invention also discloses an emulsion treatment system which comprises the abovementioned horizontal magnetic suspension type hydraulic centrifugal separating device. The horizontal magnetic suspension type hydraulic centrifugal separating device has the advantages of being simple in structure, low in energy consumption, environmentally friendly, and energy saving.