The utility model relates to a variable frequency centrifuge, which mainly comprises a central feeding pipe, a casing, a screw conveyor, spiral blades, a rotating drum, an overflow hole, a discharge hole, two motors, a frequency inverter and the like. The central feeding pipe is connected with the casing and extends into the casing, the outer side of the central feeding pipe is provided with the screw conveyor, the screw conveyor is provided with a plurality of spiral blades, the rotating drum is arranged on the outer sides of the spiral blades and packages the screw conveyor, the spiral blades and the part of the central feeding pipe extending into the shell, the lower part of the large end of the rotating drum is provided with the overflow hole, the lower part of the small end of the rotating drum is provided with the discharge hole, and the two motors are both connected with the frequency inverter and respectively control the rotating speeds of the screw conveyor and the rotating drum through the frequency inverter, so as to realize the separation of suspension in different situations. The utility model simplifies the centrifugal separation of ammonium chloride-methanol aqueous solution and glycine crystals during glycine production, reduces the labor intensity, saves the operating time and simultaneously lowers the methanol consumption.