Existing studies have shown that microplastics can cause male reproductive damage, but the effect of nanoplastics on female reproductive ability is rarely studied. The effect of PS-NPs (polystyrene nanoplastics) on the morphology of human granulosa-like tumor cells (KGN) was observed and photographed by optical microscope. CCK8 and LDH kits were used to detect the viability and damage of KGN cells exposed to 0, 25, 50, 75, 100, 125 and 150 μg/mL of PS-NPs, and the IC50 value of half inhibition of KGN cells by PS-NPs is 130.4 μg/mL. The ROS accumulation in KGN cells after exposure to 200 μg/mL of PS-NPs is significantly increase. The results showed that with the increase of the concentration of 50 nm PS-NPs, the morphology of KGN cells was significantly changed, the cell viability was significantly decreased, and the cell damage rate was significantly increased. These results provide evidence for the toxicity of PS-NPs in female reproduction.