A mesocrystal ZnCo2O4 on reduced graphene oxide (rGO) nano-composite was successfully synthesized by a low temperature annealing of bimetal organic frameworks on rGO. In this nano-composite, rGO nanosheets worked as the two-dimensional support to significantly improve the dispersity and conductivity of nano-composites. The mesoporous ZnCo2O4 crystal derived from ZnCo-ZIF worked as the main active sites with the optimized Zn/Co ratio to ensure an ideal valence band structure as well as enhanced visible-light harvesting properties. The as prepared rGO@ZnCo2O4 nano-composites showed a remarkable activity in visible-light photocatalytic NO oxidation with the conversion of 83.8% under visible light and 92.6% under simulated solar light. It also exhibited a higher stability than that of N-doped TiO2, thereby making this nano-composite as a promising and stable photocatalyst for environmental remediation.