Thermal printer and print data backup method thereof

The invention provides a thermal printer and a print data backup method thereof. The backup method comprises a printing step and a backup step; the printing step is a process of receiving print data, parsing the print data, generating image data, obtaining a printing trigger signal, printing according to the image data, obtaining a printing end signal, and completing the printing step; the backup step is a process of obtaining the image data when the printing trigger signal is triggered, and saving the image data as a backup file when the printing end signal is triggered. According to the scheme, when the printing trigger signal is triggered, the image data for imaging in a thermal film is obtained, and when the printing end signal is triggered, the image data is saved as the backup file in a picture format; the backup file and the printed document are consistent, the saving in the picture format makes it convenient for transmission and looking up, and the scheme has the properties of authenticity, legality a