Abstract: As a coal preparation plant works with streamlined continuous production process, the failure of any link may cause breakdown of the overall plant system. For a large-sized coking plant working with 4 different cleaning systems, ensuring the uninterrupted plant operation is particulary important. The key cleaning systems and process equipment of Tianzhuang Coal Preparation Plant, including the stand-by, idle and operational systems and process equipment, and each or per set of equipment, are all of redundant design in capacity for ensuring their reliability. The design method and the practical experience may serve as a reference for optimum design of large-sized coal preparation plants.