CuBi2O4 is a promising p-type semiconductor material with a theoretical maximum current density of about 19.7 mA cm‒2. Although CuBi2O4 has a very high theoretical photocurrent, its poor charge transmission efficiency makes its actual photocurrent far less than its theoretical values. Herein, an in situ modification method is adopted to prepare a photocathode material with Ag as conductive channels. A metal–organic coating method is used to introduce Ag conductive channels, promoting the charge transmission between grains. Ag particles play the role of electrical connection, and improve the separation and transmission of carriers, so as to obtain enhanced photocurrent density.Graphical Abstract: In situ formed Ag conductive channels significantly enhanced the PEC performance of CuBi2O4 photocathodes.