TSCY combined drum sieve can be used to process raw materials in the rice mill, flour mill, vertical silos of grains and other industries. Similar to other pre-cleaning devices, it is mainly to eliminate large impurity in the raw material, such as straws, wheat straws, scraps of paper, soil block, corn leaves, corn cobs and other wastes, avoiding faults and damage in the machine and conveyer devices. With high output, low energy consumption and easy installation, this machine needs minimal space and maintenance. The sieve is easy to be replaced. It has a unique transmission mechanism, feeding mechanism as well as an extended sieve, lengthening the sieving process of the materials. In accordance with the quality of the material, the machine is equipped with proper sieve meshes to reach the output requirement and separating. Moreover, replacing riding wheels and sieve rollers subject to damage is more convenient, for each riding wheel has a replacing hole.