The invention discloses a detection method of a coiled lithium ion battery. The method comprises the following steps: carrying out difference treatment on the selected characteristic area image of a coiled lithium battery, and carrying out threshold value treatment on the difference treated coiled lithium ion battery image; carrying out electrode extraction on the threshold value treated image, that is, contour extraction and refinement treatment on the threshold treated image in order to obtain line segment data representing a cathode sheet; filtering the cathode line segment data; and correcting lost image data of the threshold value treated image. The purposes of strong anti-interference capability and low fault alarming and missed alarming rate are realized.