The invention discloses a preparation method of a continuous filament of an
asphalt-based carbon
fiber, and belongs to the field of carbon
fiber production. The preparation method solves the problems that the existing
spinning speed is lower, the
fiber bundle damage is large, the infusibility efficiency is low, and doubling and
embrittlement are easy. The preparation method comprises the specific process steps that a,
spinning asphalt is extruded into fines by
spinning position fusion, humidified, oiled and bundled to form a protogenic
asphalt fiber bundle; b, double roller stranding and tensioning are conducted; c, the asphalt
fiber bundle is wound on a spinning roller sleeve; d, an asphalt fiber reel is immersed in an oxidability
liquid phase, and a liquid-phase oxidized
fiber bundle reel is obtained; e, the reel is immersed in a high-temperature-resistant oil solution; the filament is unreeled and rollers are removed at a
low speed; the oxidized fiber bundle continuously enters a continuous infusible furnace and a continuous low-temperature pre-
carbonization furnace to form a pre-
carbonization fiber bundle reel; and f, drawing heat treatment is conducted through a continuous carbon-fiber high-temperature
carbonization furnace and a graphitization furnace, and then the continuous filament of the asphalt-based carbon fiber is obtained.