Nylon powder material for selective laser sintering and preparation method thereof

The invention discloses a nylon powder material for selective laser sintering and a preparation method thereof, and the preparation method comprises the following steps: step 1, adding 100 parts of a nylon raw material, 0.5-2 parts of an end-capping reagent and deionized water into a polymerization kettle to carry out polymerization reaction, and then extruding granules to obtain nylon granules with the melt index of 60-200g/10min; 2, the nylon granules are subjected to a cryogenic crushing process and a graded screening process, and nylon powder is prepared; 3, the nylon powder prepared in the step 2 is added from the top end of the heat treatment tower, the nylon powder with the average particle size being 35-70 microns, the span being 0.6-2.3 and the melt index being 20-50 g/10 min is prepared; and 4, carrying out a graded screening process on the nylon powder prepared in the step 3, and adding a flow promoter to prepare the nylon powder material for selective laser sintering. The low-molecular-weight and