The creation of a phase junction structure in photocatalysts is a wise approach to promote photocatalytic performance, as phase junctions possess the potential to inhibit the recombination of photoinduced charge carriers. Here, Bi4V2O11 nanofibers with an alpha-beta phase junction are fabricated via electrospinning with subsequent calcination. Electrospinning offers the opportunity to keep alpha-Bi4V2O11 from transforming into beta-Bi4V2O11 completely due to an electrospinning retardation effect, leading to the formation of an alpha-beta Bi4V2O11 phase junction. Furthermore, the alpha-beta Bi4V2O11 phase junction realizes a well-established type-II band alignment. Photoelectrochemical measurements and photoluminescence spectroscopic investigations demonstrate that the phase junction structure has a significant impact on the separation and transfer of photogenerated electrons and holes. Thus, the alpha-beta phase junction on Bi4V2O11 holds the key to achieving promoted efficiency in the photocatalysis process.