Adipic acid (AA) is a crucial feedstock for nylon polymers, and is industrially produced by thermal oxidation of cyclohexanone/cyclohexanol mixture (KA oil). However, this process consumes large quantities of corrosive nitric acid as oxidants, while emits ozone‐depleting greenhouse gas N2O. Here, an electrocatalytic strategy for selective oxidation of KA oil to AA coupled with H2 evolution over a Co3O4/graphdiyne cooperative catalyst (Co3O4/GDY) is reported. The Co3O4/GDY displays high electrooxidation activity of KA oil to AA (100 mA cm−2 at ≈1.5 V vs RHE), outperforming all the reported findings. Detailed ex situ and in situ experimental studies, theoretical calculations, and molecular dynamic simulations reveal that GDY not only facilitates the enrichment of cyclohexanone on the catalyst surface in aqueous medium, but also upshifts the d‐band center of Co sites, strengthening the adsorption/activation of cyclohexanone. This study offers a green route for AA synthesis and proposes a GDY interface engineering strategy for efficient electrooxidation. Highly efficient electrooxidation of cyclohexanone/cyclohexanol mixture (KA oil) into adipic acid coupled with H2 evolution is achieved over a Co3O4/graphdiyne cooperative catalyst (Co3O4/GDY). GDY, as an electron modifier, can upshift the d‐band center of Co3O4, which facilitates the enrichment, adsorption, and activation of cyclohexanone on the catalyst surface in aqueous solutions, resulting in top‐level activity (100 mA cm−2 at ≈1.5 V vs RHE) and high yield of AA (>82%).