After 6 months of intervention, IEC program obtained significant results: a reduction in the rate of patients who skipped taking methadone for 3 days and over 3 consecutive days in the last 3 months, with an intervention efficiency of 27.0% and 55.6%; Reducing risk factors such as illicit drug use, urine test (+) with heroin, and drug-using peers with intervention efficiency of 43.7%, 38.3% and 16.2%; Significantly increasing QoL score of psychological and environmental aspects of patients.