Abstract: The polyamide(PA) and polystyrene (PS) powders are compounded to prepare a series of experimental samples by a selective laser sintering machine, and the microstructure, dimensional accuracy, density, bending strength and surface roughness of the samples were characterized to explore the effect of composition ratio on the performance of the PS/PA samples. The results indicated that the bonding degree of PS and PA powders in the samples increased with an increase of PA content, and the bending section of the samples became flatter. The dimensional accuracy of the samples was better than other experimental groups at the PS/PA weight ratio of 1/4. The density of the samples also increased gradually with an increase of PA content. The density of the samples became larger and closer to each other at the PS/PA weight ratios of 1/2, 1/3, 1/4, and 1/5. The bending strength of the samples presented an upward trend with an increase of PA content and increased at the PS/PA weight ratios of 1/2, 1/3, 1/4 and 1/5. In addition, the samples exhibited a minimum in surface roughness at the PS/PA weight ratio of 1/4.