As a solids control equipment of the second stage in drilling operation, desander is used to remove harmful solid particles of 44-74µm in drillingliquid.Suspending particles can be separated from the liquid under the centrifugal acceleration, by use of working principle of centrifugal subsidence. At present time, six types,JZQJ300×2,JZQJ250×2, JZQJ200×2 andJZQJ300×1, JZQJ250×1, JZQJ200×1are available. The former applies to over 3000-meter-long drills, and the latter applies to small drills of less than 3000 meters and service rig.