Abstract: An introduction is made in the paper to the structure and operating principle of the pneumatically-actuated striking mechanism fitted on the clean coal slime sieve bend,and such a bend working at Linxi Mine Coal Preparation Plant is cited by way of example. Based on the data obtained through conducting experiments on optimization of parameters of the striking mechanism on the bend working at the plant,calculation is made of the yield and partition coefficient of each size fraction by following the method and procedures set forth in GB /715716-2005——Methods for Evaluation of Performance of Coal Screening Equipment. The partition coefficient of each size fraction calculated is then taken as a basis for predicting the working performance of the 2-stage clean coal slime sieve bends used at a coking coal plant. Following that an analysis and comparison are made with the actual working performance of the 2-stage system in operation. Comparison indicates that a single-stage clean coal slime sieve bend fitted with sieve bend can replace a 2-stage version working in series.