The irrational belief is an important obstacle to treatment and rehabilitation of drug abusers. Drug abusers irrational beliefs is mainly reflected in the addiction motivation，cognitive addiction bias and externalizing，lack of knowledge on addiction and sense of self-worth. The belief that they will not be tied to addiction and an absolute belief in the efficacy of drugs has prompted them to fall into the trap of drug addiction. Cognition warp hinder the persistence of treatment and willingness to initiate treatment. These cognition warp includeflattering themselves have the ability to control addiction，flattering themselves can be responsible for their own and firmly believing drug is as well as cigarettes. The lack of knowledge on addiction is the main cause of the early withdrawal of drug abusers. External attribution，problem expansion and the sense of self-worth become the serious obstacle to the return of drug abusers to society. Social workers should pay attention to identify drug abusers irrational beliefs in drug treatment.