Due to the unstability and prone to aggregation and precipitation of gold nanoparticles （AuNPs） synthesized by classical Turkevitch method， this paper aimed to increase the stability of AuNPs by adding bacteriocin in the reaction mixture as capping agent. At the same time， AuNPs with good penetration properties can help bacteriocin get inside the bacteria to exhibit the antimicrobial activity. The synthesis conditions of temperature， pH and time was optimized by considering the maximum absorption peak， Zeta point， average particle size， polydispersity of AuNPs particles and determine the AuNPs preparation conditions with small average particle size and high stability. The AuNPs solution was incubated with the bacterial cells and transmission electron microscopy（TEM） pictures were taken to exam the AuNPs morphology and their interaction with bacterial cells. The results indicated that the AuNPs prepared with pH 5 at 100 ℃ for 30 min in mixture reached the largest UV-vis absorption peak， highest Zeta potential absolute value， and the smallest average particle size. The polydispersity index is low， and it is not easy to aggregate， which is the best preparation condition for AuNPs. TEM showed that AuNPs were spherical particle with a size range of 15-20 nm. During the interaction with bacteria， AuNPs can destroy the cell wall and cell membrane to get inside the bacterial cells.