Carton sealing machine by the middle before and after the seal up and down, into the 90-degree angle by pushing the board into the corner box sealing machine, photoelectric detection of the machine according to carton specifications automatically adjust the width and height of the machine. No need to manually adjust the machine, simple, convenient and fast. Automatically adjust the carton specifications, at the same time automatically seal the upper and lower corners of the carton, heal, fast, stable; machine using PLC control, simple operation, easy maintenance, more stable performance.