This paper describes the structure and principle of the blade x-ray beam position monitor of Shanghai Synchrotron Radiation Facility
with the theoretical analysis and calibration result of the XBPM system.Coefficient of the calibration was calculated from the least square method.Based on this result
the linear range and measurement accuracy were discussed.To meet the measurement accuracy of 10 μm
the linear range of the XBPM system was ±500μm
the calibration error was 3.25μm
the absolute position error was about 11μm and the relative position error was about 3 μm.