To evaluate the quality of moxa floss by observing the microscopic properties，determining the dust content and micro-grinding degree.Methods:In this experiment，33 samples of machine-processed and laboratory-made moxa floss were tested.The differences of dust content，micro-grinding degree and Micro-properties of moxa floss were compared and analyzed from different processing proportions and processing technologies.Results:The results showed that the micro characteristics of different processing ratio of moxa floss were obviously different，and compared with the laboratory-made moxa floss，the filament winding of machine-processed ones was obviously in the shape of a ball.There were significant differences in the dust content of fine and general moxa floss among different processing ratios (P<0.05):fine moxa velvet＜rough moxa floss＜general moxa floss.There were significant differences in the degree of micro-grinding (P<0.05):rough moxa floss＜general moxa floss＜fine moxa floss.There was no significant difference in the dust content of moxa floss among different processing technologies (P>0.05).There was a linear relationship between the micro-grinding degree and the processing ratio of moxa floss(P<0.05).Conclusion:The microscopic characteristics can distinguish the different processing technology of moxa floss.The dust content can reflect the fineness of moxa floss under the condition of high crushing degree，but there are some defects.The micro-grinding degree can reflect the fineness of moxa floss objectively.