Abstract: The mass flow meters have to be removed from the line for routine testing to ensure the accuracy of flavoring and casing application,it is troublesome and apt to damaged the meter,and the production is affected.Therefore,an online calibrating method was proposed by taking the strips casing system as an example.Calibrate the electronic belt weigher in front of casing cylinder and the standby electronic platform balance,and check the flow meter's zero-point as well,first,then purge and clean the pipeline and casing tank of casing cylinder,take the casing's weight and trace record data continuously,meantime,calculate the measuring error of the flow meter,accuracy of casing applying and control accuracy,and adjust PID control parameters and flow meter operation software accordingly.Trace the data of 3 continuous batches until the set standard is met.The method is convenient,practical,and accurate.