The soft X-ray experimental platform is constructed for accurate calibrating detector of inertial confinement fusion (ICF) on Beijing synchrotron radiation facility (BSRF).It is the only one in our country.The platform mainly consists of two synchrotron radiation beamlines (energy range:0.05-6 keV),high precision reflectometer,X-ray standard detector of ion chamber,and some calibrating devices for the detector.The soft X-ray beamline (4B7B) andmiddle X-ray beamline(4B7A) are constructed successfully.Their targets and parameters are achieved and excel the original designs.A lot of detectors are calibrated with the platform.They are X-ray detector (XRD),mirror and multilayer,filter,transmission grating,charge coupled device (CCD),and other new type of detecting elements and devices,such as crystal and image plate,with which lots of achievements are obtained in ICF experiments.The platform also has many applications in other fields such as optics,material,astronomy,metrology,and Z-pinch′s detector calibration,etc.