Automatic reducing yarn core and yarn fluffing device

The invention discloses an automatic variable-diameter yarn core and yarn fluffing device, and belongs to the technical field of textile, the automatic variable-diameter yarn core and yarn fluffing device comprises a table top, a cotton core module, an upper clamp module and a cotton loosening module, and the reverse side of the table top is provided with a first driving part; the cotton core module comprises a fixed base and a plurality of yarn core bent outer walls adjustably arranged on the fixed base, and one end of the fixed base is detachably connected to a large belt wheel in the first driving part; the upper clamp module comprises a gear bottom plate, the gear bottom plate is supported on the table top through an F-shaped seat, and the gear bottom plate is connected with an upper pressing die through a rotatable arm rod; the cotton loosening module comprises a first base fixed to the table top, cams are rotationally installed at the four corners of the first base correspondingly, a push plate is movab