The invention relates to an insulator salt density data bar processing method and a processing system. The insulator salt density data bar processing method comprises the following steps: the originalinsulator salt density data of an insulator salt density online monitoring device are acquired, wherein the original insulator salt density data contain multiple data bars, and each database containsa salt density data item and a dust density data item; according to the numerical value of the salt density data item, whether the salt density data item is abnormal is judged, and according to the numerical value of the dust density data item, whether the dust density data item is abnormal is judged; a data bar with abnormality existing in at least one of the salt density data item and the dustdensity data item is judged to be an abnormal data bar; and the abnormal data bar is eliminated, and a normal data bar is kept. Due to the above insulator salt density data bar processing method and the processing system of the invention, the abnormal data bar can be picked out and eliminated, and the contamination flashover characteristics and the contamination flashover risk analysis accuracy ofthe transmission line insulator are improved.