The invention relates to a track generating method which includes firstly finding out the approach line of the upper edge or the lower edge of a line of printing characters, secondly finding out two printing lines of another edge of the printing characters by utilizing the approach line, then finding out two printing lines of the edge of the printing characters by taking the two printing lines asa benchmark and finally deleting unnecessary printing lines by utilizing the relation between the printing lines and the edge reference points of the printing characters; therefore, the printing lines solved by the invention can be used for subsequently identifying the character directivity, the character size and the punctuations, thereby improving the efficiency and accuracy of character identification.