A twin-screw extrusion device is disclosed, which includes a barrel and a twin-screw mechanism, the twin-screw mechanism includes a first screw, a second screw and a drive assembly, the drive assembly includes a plurality of idler gears and two mutually engaged elliptical gears, one of the elliptical gears is fixedly connected to the first screw, the other elliptical gear synchronously rotates with one of the idler gears, the last idler gear is fixedly connected to the second screw, a rotation speed of the first screw is .sub.1=N, an eccentricity of each of the elliptical gears is k, 0<k<0.8, an included angle between a connecting line of the first screw and the second screw and a long axis of each of the elliptical gears is , and a rotation speed of the second screw is .sub.2, satisfying ${}_2=\frac{\left(1-k^2\right)N}{1-2k\cos +k^2}.$

A twin-screw extrusion device is disclosed, which includes a barrel and a twin-screw mechanism, the twin-screw mechanism includes a first screw, a second screw and a drive assembly, the drive assembly includes a plurality of idler gears and two mutually engaged elliptical gears, one of the elliptical gears is fixedly connected to the first screw, the other elliptical gear synchronously rotates with one of the idler gears, the last idler gear is fixedly connected to the second screw, a rotation speed of the first screw is .sub.1=N, an eccentricity of each of the elliptical gears is k, 0<k<0.8, an included angle between a connecting line of the first screw and the second screw and a long axis of each of the elliptical gears is , and a rotation speed of the second screw is .sub.2, satisfying ${}_2=\frac{\left(1-k^2\right)N}{1-2k\cos +k^2}.$

The present application discloses a continuous dynamic and efficient devolatilization method for a polymer/volatile system based on high mass transfer interfaces, including the following steps: providing a dynamic single-screw devolatilizer, feeding a polymer solution to the devolatilizer, wherein the polymer solution includes polymer and volatile substances with small molecule weight, and the volatile substances include organic solvents, residual monomers, water or reaction by-products; conveying and compressing polymer materials by the screw downstream a devolatilization section, and extruding the polymer materials out of the dynamic single-screw devolatilizer directly; or providing a side-feeding extruder downstream of the devolatilization section and feeding plastic additives into a devolatilized polymer melt, and then melt blending the plastic additives with the devolatilized polymer melt at an end of the dynamic single-screw devolatilizer before exiting the dynamic single-screw devolatilizer.