Abstract: In order to improve the screening efficiency and operation stability of large particle cylin⁃ drical screen in the treatment of high viscosity and low fluidity pulp，aiming at the problems of material ag⁃ glomeration，sieve hole blockage and poor slag discharge，which lead to the performance degradation of cylinder screen，the four-dimensional collaborative optimization of increasing effective screen surface， roller-gear shaftless drive，straight-through slag discharge and constant pressure flushing is carried out. Through the optimization of structural parameters，the force check of driving system and the analysis of screening dynamics，the utilization rate of screen surface is improved，the transmission load is homoge⁃ nized and the flow field of slag discharge is self-regulated.The industrial test results show that under the conditions of cylinder speed 3 r/min，sieve hole 4 mm and flushing water pressure ≥0.10 MPa，the average processing capacity of the equipment is 120 t/h，the screening efficiency is increased to 88.6%，the contin⁃ uous and stable operation of more than 1 000 h without blockage can be achieved，and the unit processing energy consumption is reduced by about 12%.The optimization scheme can effectively improve the classifi⁃ cation and desliming performance of the cylindrical screen under complex slurry conditions，and provide a releasabletheoretical basis and engineering reference for the design of efficient screening equipment for large particles and high viscosity slurry.

Key words: cylinder screen, large particle minerals, slag separation, screening, optimization design