Membrane material flatness detection method

The invention is suitable for the field of detection, and discloses a film material flatness detection method, which comprises the following steps: determining a plurality of detection positions of a rolled film material according to the width of the rolled film material; respectively measuring and recording the perimeter values of the membrane material at the plurality of detection positions; comparing the membrane material perimeter values of all the detection positions, finding out the minimum membrane material perimeter value as a reference value, and respectively calculating difference values between the membrane material perimeter values of the detection positions except the reference value and the reference value; if the difference values between the membrane material perimeter values of all the detection positions except the reference value and the reference value are smaller than a first threshold value, the flatness of the rolled membrane material is qualified, and if the difference value between th