Device and method for online improving coating concentricity in optical fiber drawing

The invention discloses a device for online improving the coating concentricity in optical fiber drawing. The device comprises a die holder which is arranged corresponding to a drawing furnace, the die holder is installed on a die holder platform, a rotatable die is installed in the die holder, the two sides of the die holder are provided with a first spiral micrometer and a second spiral micrometer respectively, and the bottom end of the die holder platform is provided with a third spiral micrometer and a fourth spiral micrometer; fluctuations of the concentricity of an optical fiber in the drawing process are online detected through an optical fiber concentricity online detector, and positions of the die holder platform in the Z direction and the X direction are adjusted by adjusting the third spiral micrometer and the fourth spiral micrometer; the height H is adjusted by adjusting the first spiral micrometer and the second spiral micrometer, the inclination angle of the die holder platform is adjusted, the