In order to explore the influence of voyage and the intake of probiotics Probio-X■ on the intestinal lactic acid bacteria. Taking 27 long-sea-voyage sailors as the research subjects， they are randomly divided into probiotics group （n = 11） and placebo group （n = 16）. The intestinal LAB was detected by the combination of LAB specific primer amplification and PacBio SMRT sequencing technology A total of 57 genera and 160 species were detected in the intestines of 27 long-sea-voyage volunteers. At the species level， they were mainly composed of Streptococcus thermophilus（31.06%）， Lactobacillus ruminis（9.31%）， Streptococcus parasanguinis（6.90%）， Streptococcus salivarius（4.11%）， and Lactobacillus plantarum（3.47%）. After the voyage， the number of unique OTUs in the probiotic group and the placebo group increased， and the composition of the intestinal flora changed， however， NMDS analysis showed that there was no significant difference in Lactobacillus structure between the probiotics group and the placebo group， However， the average relative abundance of some species changed significantly， such as Streptococcus sanguinis and Streptococcus parasanguinis. Before the voyage， Streptococcus salivarius and Streptococcus thermophilus are the main LAB in the intestinal tract of seafarers. After ingestion of probiotics， the seafarers intestinal tract with low relative abundance was prone to change， and the relative abandance of Lactobacillus plantarum and Lactobacillus fermentum in the intestinal tract were increased. This study showed that probiotics Probio-X■ intervention can significantly inhibit the growth of Streptococcus parasanguinis and Streptococcus sanguinis in the intestinal of seafarers during the long voyage. The intake of probiotics Probio-X■ will change the LAB intestinal type of seafarers， but this change depends on the type and basic amount of the original LAB in the intestine. By studying the effect of probiotics Probio-X■ on intestinal LAB diversity of seafarers during long voyage， we hope to provide a feasible way to maintain intestinal health of seafarers during long voyage.