Through the research and analysis of the water-based and oil-based mud non-landing systems, the treatment process and core technology of two non-landing systems are summarized. In light of the actual situation of Well DY-4, a mud non-landing treatment plan based on the ordinary solid control systems has been designed, and implemented. Through modification, the non-landing system eliminated the mud pit and the settlement tank, avoiding any leakage from the whole mud circulation process of mud circulation, purification and recycling; hence, very environmentally friendly.