Abstract: The raw coal quality becomes worse and worse due to the high mining mechanization and great mining depth.Most of the coal are difficult to prepare,so the main preparation plants are dense medium ones.The proper design of production pipelines is essential for the stable operation of coal preparation plant.Determine the pipeline diameter and thickness,select the pipe fitting and valves,route the pipes according to the actual situation.Introduce the experience of pipeline layout design and disconnecting design.For ease of its installation and maintenance,optimize the design.At last,put forward some notes on pipeline installation and maintenance for dense medium coal preparation plants.