Various embodiments provide a filament replacement mechanism for a 3D printer and a 3D printing system. In those embodiments, the filament replacement mechanism includes: a support; a filament guide unit disposed on the support and including a plurality of secondary filament guide tubes and a filament guide opening connecting with the plurality of secondary filament guide tubes, where the filament guide opening is configured to be jointed with a main filament guide tube of the 3D printer; and a plurality of filament replacement units disposed on the support.

Various embodiments provide a filament replacement mechanism for a 3D printer and a 3D printing system. In those embodiments, the filament replacement mechanism includes: a support; a filament guide unit disposed on the support and including a plurality of secondary filament guide tubes and a filament guide opening connecting with the plurality of secondary filament guide tubes, where the filament guide opening is configured to be jointed with a main filament guide tube of the 3D printer, and a plurality of filament replacement units disposed on the support.

Various embodiments provide a filament replacement mechanism for a 3D printer and a 3D printing system. In those embodiments, the filament replacement mechanism includes: a support; a filament guide unit disposed on the support and including a plurality of secondary filament guide tubes and a filament guide opening connecting with the plurality of secondary filament guide tubes, where the filament guide opening is configured to be jointed with a main filament guide tube of the 3D printer, and a plurality of filament replacement units disposed on the support.