The invention discloses a sample preparation device for food safety detection, and belongs to the technical field of food safety detection. The sample preparation device for food safety detection comprises a sample preparation box, the inner wall of the sample preparation box is fixedly connected with a fixing plate, an inlet is formed in the outer wall of the sample preparation box and located above the fixing plate, the inner wall of the sample preparation box is further rotationally connected with a lead screw and a rotating shaft, the outer wall of the lead screw is in threaded connection with a placement plate, and the placement plate is slidably connected to the outer wall of the fixing plate, the outer wall of the rotating shaft is connected with a cutting mechanism, the cutting mechanism is arranged above the placement plate, through holes are formed in the outer wall of the fixing plate, three blanking openings matched with the through holes are formed in the outer wall of the placement plate, the outer wall of the sample preparation box is connected with a supporting seat, the outer wall of the supporting seat is connected with a motor, and the output end of the motor is connected with a first rotating shaft, a first gear is connected to the outer wall of the first rotating shaft; the device is simple in structure, the manufacturing cost of the device is reduced, the food safety detection cost is further reduced, and the actual use requirements can be met.