Calibration method of bending roll of heat coil box and locking device realizing same

The invention relates to a calibration method of a bending roll of a heat coil box and a locking device realizing the same. The calibration method comprises the working procedures of: after the independent calibration of an inlet bending roll is finished, lifting the inlet bending roll to a preset position, positioning and locking the inlet bending roll by using a hydraulic locking device, and then completing the press calibration of an outlet bending roll; and realizing automation through the setting of programs. In the locking device, a two-position on-off valve capable of keeping a rodless cavity airtight is connected to a hydraulic pipeline between the rodless cavity of a hydraulic cylinder and a proportional valve; the rodless cavity of the hydraulic cylinder is connected with the two-position on-off valve through a ball valve; the other end of the two-position on-off valve is respectively connected with the proportional valve and a relief valve; and the other end of the relief valve is communicated with