The invention relates to a flour production system. The system comprises a screening device, a raw wheat bin, a screening device, a first wheat processing assembly, a dampener, a wheat wetting bin, asecond wheat processing assembly, a color selector and a flour mill, the screening device comprises a box body, a screening mechanism and a magnetic separation mechanism, the box body is provided witha feeding port and a discharging port, a partition plate is arranged between the feeding port and the discharging port, the screening mechanism and the magnetic separation mechanism are located on the two sides of the partition plate, the screening mechanism comprises a screening cylinder, a spiral blade and a driving part, the screening cylinder comprises a screen, a plurality of supporting rods, a first connecting ring and a second connecting ring, the first connecting ring is rotationally connected to the box body, the second connecting ring is rotationally connected to the partition plate, an air supply hole extending along the spiral line of the spiral blade is formed in the spiral blade, the spiral blade is provided with a plurality of vent holes communicating with the air supply hole, the air supply hole communicates with an air supply piece used for supplying air, and the bottom of the box body is provided with an exhaust hole and communicates with a separation mechanism. Thew system has a relatively good wheat screening effect.