The invention belongs to the technical field of agricultural microorganisms and aquatic product processing, and particularly relates to a compound starter for lactobacillus plantarum and application thereof, wherein the compound starter is used as a microbial starter, is especially suitable for freshwater fish fermentation, and is composed of lactobacillus, pediococcus acidilactici and staphylococcus xylosus. A lactic acid bacterium, namely lactobacillus plantarum, suitable for freshwater fish fermentation is obtained through self separation and screening, and the preservation number in the China center for typical culture collection is CCTCC NO: M2012396. The compound microbial starter is prepared from lactobacillus plantarum, pediococcus acidilactici and staphylococcus xylosus, is suitable for fish product fermentation and particularly suitable for the application to preserved fish fermentation, has a sound fermenting property, has typical fermentation fragrance, and facilitates industrial production.