The invention relates to a preparing method of a long-chain nylon compound material for 3D printing. The preparing method comprises the following steps of preparing, by weight, 100 parts of long-chainnylon, 5-10 parts of
kevlar chopped
fiber, 5-15 parts of
wollastonite, 0.1-0.3 part of coupler, 3-8 parts of flexibilizer, 0.5-1 part of hyperbranched resin and 0.2-1 part of antioxygen; spraying a
coupling agent solution while stirring
wollastonite, and conducting
drying and cooling; uniformly mixing
coupling-agent-modified
wollastonite, the long-chain nylon, the
kevlar chopped
fiber, the flexibilizer, hyperbranched resin and antioxygen; adding a premixed
raw material into a double-screw extruder for
extrusion pelleting to obtain modified particles; adding the dried modified particles into asingle screw extruder to extrude out a plastic melt, and conducting hot water and cold
water treatment to obtain wires. The preparing method is suitable for large-
batch production, the prepared printing product has no obvious exposed
fiber, the stretching strength, the bending strength and the
thermal deformation temperature are high, and the size is stable.