Probiotics are a group of living microorganisms beneficial to host health when administered in adequate amounts. In recent years， the probiotic industry has thrived domestically and internationally. It has become a global research hotspot and a primary direction of industrial innovation and development by profoundly exploring and analyzing the probiotics' efficacy and health action mechanism and achieving more accurate， effective and safe probiotics for human health. The beneficial effect of probiotics is strain specific， and yet its efficacy needs to be evaluated scientifically and a unified standard for the evaluation of probiotics efficiency is required. At present， based on the systematic analysis of the research status of probiotics' regulation of intestinal flora and immunity， the Probiotics Society of the Chinese Institute of Food Science and Technology sorted out in vitro evaluation methods of whole gene sequencing technology through animal experiments， population experiments and clinical trials. Furthermore， with expert opinions， provided a set of domestic and international regulations and relevant standards. This research aimed to provide a reference for scientific research， standard and regulation formulation， industrial application， and scientific popularization of probiotics.