In order to improve the quality of quinoa noodles and inhibit the negative effect of rancid taste caused by oil oxidation on noodles in processing quinoa powder, the defatting treatment of quinoa powder was introduced, and the volatile substances in common noodles, quinoa noodles, defatted quinoa noodles and their soups were analyzed. In experiment, n-hexane was used as the leaching solvent for defatting, while the volatile flavor compounds in quinoa noodles and defatted quinoa noodles were detected by solid-phase microextraction technology and gas chromatography-mass spectrometry (GC/MS). Results show that repeated defatting for three times could effectively reduce the oil content of quinoa. Compared with wheat flour, the aldehydes, furans and ketones in the volatile flavor substances of quinoa noodles were increased. The grass and wine taste of quinoa flour products could be reduced by defatting treatment. The ketones and esters in the volatile flavor substances of defatted quinoa flour products showed significant difference. Defatting treatment can improve the flavor of quinoa, and has little effect on the structure of protein and starch in quinoa flour. Thus, it can be applied as a processing method for quinoa in the future.