The invention relates to an automatic polishing machine and an automatic polishing method of a silk-screen printing scraping strip. The automatic polishing machine comprises a grinding wheel, a grinding wheel positioning mechanism, a grinding wheel driving motor, a scraping strip locking mechanism, a scraping strip position sensor, a controller and a scraping strip moving servo mechanism, wherein the scraping strip position sensor is used for measuring an initial position of the scraping strip; the controller is used for controlling the scraping strip moving servo mechanism to move the scraping strip locking mechanism to a working position according to the initial position and a moving target position of the scraping strip; and the grinding wheel driving motor is used for driving the grinding wheel to polish the scraping strip moved to the working position under the control of the controller. With the adoption of the automatic polishing machine and the automatic polishing method of the silk-screen printing scraping strip, the polishing accuracy of the scraping strip is improved; the surface smoothness of the scraping strip is ensured; the depth of polishing at every time is controlled; automated operation is realized in the overall process; personnel can operate easily the automatic polishing machine; polishing parameters are visual and adjustable; and the automatic polishing machine can be adjusted according to different requirements, and has a wider application range.