The solid control equipment is the most important part of the petroleum machinery. It is the purification system of drilling fluid in the drilling rig industry. The solid control equipment is the equipment to deal with the recovery of the drilling fluid (mud) returning to the surface of the wellhead. The solid control system can effectively separate the large drills, barite and other large solid particles from the back of the wellhead (mud), and the treated drilling fluid (mud) can be reused. So as to reduce drilling cost and environmental protection. The common control equipment includes mud vibrating screen, mud cleaner, desilter, degasser, vacuum degasser, liquid gas separator, mud agitator, jet mixing device, electronic ignition device, mud gun, screw conveyor, sand pump, shear pump, centrifuge and so on. The purification process of the drilling fluid solid control equipment is roughly as follows: the wellhead (back out drilling fluid), drilling fluid vibrating screen, vacuum degasser, drilling fluid desilter, degasser, drilling fluid centrifuge and purified drilling fluid back to the wellhead.