Abstract: There was considerable amount of tipping paper remaining on the exhausted bobbin after automatic splicing in PASSIM assembler.Omron CPM1A-PLC was used to take the place of the counter in original splicing system,and further,a new function of manual splicing during machine running was incorporated,the control precision was increased effectively.The remainding tipping paper was reduced from 25.04 m to 4.5 m,the tipping paper consumption decreased,and production cost was saved accordingly.