Poly-gamma-glutamic acid (-PGA) is an extracellularly produced biodegradable polymer, which has been widely used as agricultural fertilizer, mineral fortifier, cosmetic moisturizer, and drug carrier. This study firstly discovered that lichenysin, as a biosurfactant, showed the capability to enhance -PGA production in Bacillus licheniformis. The exogenous addition of lichenysin improved the -PGA yield up to 17.9% and 21.9%, respectively, in the native strain B. licheniformis WX-02 and the lichenysin-deficient strain B. licheniformis WX02-lchAC. The capability of intracellular biosynthesis of lichenysin was positively correlated with -PGA production. The yield of -PGA increased by 25.1% in the lichenysin-enhanced strain B. licheniformis WX02-Psrflch and decreased by 12.2% in the lichenysin-deficient strain WX02-lchAC. Analysis of key enzyme activities and gene expression in the TCA cycle, precursor glutamate synthesis, and -PGA synthesis pathway revealed that the existence of lichenysin led to increased -PGA via shifting the carbon flux in the TCA cycle towards glutamate and -PGA biosynthetic pathways, minimizing by-product formation, and facilitating the uptake of extracellular substrates and the polymerization of glutamate to -PGA. Insight into the mechanisms of enhanced production of -PGA by lichenysin would define the essential parameters involved in -PGA biosynthesis and provide the basis for large-scale production of gamma-PGA.