The invention relates to the technical field of resource utilization of oilfield solid wastes, provides an interface material for dehydrating oilfield produced liquid as well as a preparation method and application thereof and further provides a lipophilic and hydrophobic type interface material which takes the interface material for dehydrating the oilfield produced liquid as a raw material. Theinterface material for dehydrating the oilfield produced liquid is prepared from sludge produced by an oilfield sewage treatment system, fly ash and cement. The interface material for dehydrating theoilfield produced liquid, provided by the invention, has the advantages of sable chemical performance, firm texture, low abrasion rate, strong lipophilic and hydrophobic performance and good dehydration effect; a preparation technology is simple and the interface material is applied to the field of rapid agglomeration and dehydration of the oilfield produced liquid; the environment pollution problem caused by the sludge produced by the oilfield sewage treatment system in an oilfield development process and industrial waste fly ash is solved, and produced wastes also can be circularly utilized;the interface material for dehydrating the oilfield produced liquid has the advantages of cost reduction, energy source saving and environment-friendly protection; meanwhile, the lipophilic and hydrophobic interface material can be used for the field of deep purification of oilfield sewage.