A device for fixing a tail end of a filament to a filament spool is provided. The device includes a filament threading module having a filament feeding module and a filament guide mechanism. The filament feeding module is configured to clamp the filament and pass the tail end of the filament through a first threading hole on the filament spool. And the filament guide mechanism including a filament guide assembly is used to guide the tail end to pass through a second threading hole on the filament spool after the tail end of the filament has passed through the first threading hole. The filament guide assembly including a filament guide and a filament driver. The filament driver is configured to move the filament guide assembly towards or away from the filament spool.