Abstract: There are a large number of mud additives in drilling mud, thus the solid-liquid separation method can be used to reduce the volume of waste mud and keep the effective components in the solid phase, which can be used to compound mud again. The experiments show that: all kinds of conventional functions, the anti-aging function and the anti-pollution function of the mud compounded again were up to the requirements of original mud ; in the meantime, adding amount of the mud additives was just one third of that of original mud, therefore the cost was reduced and this process has obvious economy benefits, social benefits and environment benefits