The invention discloses a phase-separating device for the production of 2-methyl-5-pyrazinecarboxylic acid, relates to the technical field of phase-separating equipment, and comprises a fixing frame, and a mounting hole is opened in the middle of the top of the fixing frame, and the mounting hole is A centrifugal cylinder is fixed on the inner wall of the centrifugal cylinder, and a drum is arranged inside the centrifugal cylinder. A fixed ring plate is fixed on the top position of the inner peripheral wall of the centrifugal cylinder, and a rotating ring plate is installed on the inner ring of the fixed ring plate. The inner ring of the rotating ring plate is fixed on the outer peripheral wall of the rotating shaft. When the extraction time set by the single-chip microcomputer of the present invention is reached, the second electromagnetic valve is opened and the first electromagnetic valve is closed. At this time, the light phase liquid gradually flows out, and the inert gas slowly returns to the anti-permeation rubber sleeve, and the anti-infiltration rubber sleeve gradually expands. Then continuously push the light phase tube to move gradually so that it can be in contact with the light phase liquid all the time until the light phase liquid flows out completely, which can increase the collection rate of the light phase liquid and reduce waste.