Abstract: Nuclear belt weigher was usually calibrated by simulating the operating status in the processing line,while tobacco was fed and spreaded by hands.The calibration process was time-consuming and laboursome,and the precision of the weigher was affected greatly.For the nuclear weigher at the blending station,where cut tobacco,cut expanded tobacco,cut reconstituted tobacco and cut stem were blended together,a fast and simple on-line calibrating method was introduced,wherein,the belt weigher of down stream was cali-brated first,then the readings of the belt weigher was used as the standard for transfer of measured value,and the accumulated weight of nuclear weigher was calculated with the blending ratios.It is fast,convenient and labor-saving,and also meets the requirement of the transfer of calibrated measured values.