A CDC biofilm reactor was used in the study to simulate the drinking water distribution system. The distribution characteristics of six typical antibiotic-resistant bacteria (ARB) in the three-phase interface of water, biofilm and particulate matter were evaluated. After 30days operation, the concentration of chlorine in the effluent decreased from 0.66mg/L to 0.26mg/L, the turbidity and the concentration of particulate matter increased from 0.08NTU and 377counts/mL to 0.86NTU and 4151counts/mL. The largest number of ARB in the effluent were streptomycin and ampicillin resistant bacteria (432CFU/100mL and 155CFU/100mL, respectively), which was much higher than the number of resistant bacteria in the inlet. The highest level of ARB in the inlet were erythromycin and ampicillin resistant bacteria, which were only 36CFU/100mL and 99CFU/100mL, respectively. In the biofilm phase, the total number of heterotrophic bacteria and total number of cells reached as high as 4089CFU/cm²and 1.5×106cells/cm². Streptomycin and erythromycin resistance bacteria were 3432CFU/cm² and 2508CFU/cm², the ratio of which to the total heterotrophic bacteria were 83.9% and 61.4%. The resistant bacteria ratio of chloramphenicol and ampicillin in the particulate phase were approximately 45%. Both biofilm and particulate matters can provide a safe and stable place for bacterial growth, and protect bacteria from the residual disinfectants and some antibiotics, which facilitates antibiotic resistant bacteria propagation and poses a greater threat to human health.