Glass calender capable of accurately adjusting gap pressure of main roller

The invention relates to a glass calender capable of accurately adjusting the gap pressure of a main roller, an upper roller assembly of the glass calender comprises a seat arm and a pressing arm, the seat arm is provided with an upper roller bearing seat, the pressing arm is provided with a pressing column mechanism, the pressing column mechanism comprises a beam frame, a column sleeve, a pressing column, a bidirectional stepping motor, a pressure sensor and a PLC (Programmable Logic Controller), the center of the beam frame is hinged to the free end of the pressing arm, one end of the beam frame is rotationally connected with the column sleeve through a bearing, the other end of the beam frame is connected with the top of the pressure sensor, the lower end of the column sleeve is in threaded connection with the pressing column, and the upper end of the column sleeve is fixedly connected with an output shaft of the bidirectional stepping motor. And the input end and the output end of the PLC are respectively