Photocatalytic oxidation desulfurization is presently challenged with low quantum efficiency and high combination rate of electron-hole, and the key to success is to design efficient multicomponent composite photocatalysts. This work successfully synthesized Z-scheme photocatalysts ZnM-LDHs/g-C3N4 (M = Al, Cr) by the electrostatic self-assembly, analyzed their work mechanism through various characterization technique such as XPS, PL, TRPL, and ESR, explored the activity enhanced mechanism, and revealed the reason of their catalytic activity difference. Photocatalytic oxidation/extraction desulfurization of ZnAI-LDHs/g-C3N4 and ZnCr-LDHs/g-C3N4 can achieve 99.8 and 96.6%, respectively, in 3 h for model oil. The results are instructive for the structure design and study of efficient photocatalysts in desulfurization.