Photocatalytic behaviors of isostructural metal doped metal-organic frameworks were rarely discussed in the field of metal-organic frameworks. Herein, a series of 2D isomorphous Co2+/Zi(i2)+ metal-doped metal-organic frameworks, namely, [M(tpbpc)(bdc)(0.5)-H2O].solvent (M = Co (1), Co0.545Zn0.455 (2), Co-0.2165 Zn-0.7835 (3) Co0.258Zn0.9742 (4) Zn (5), Htpbpc = 4'[4,2';6',4 ''] terpyridin-4'-yl-biphenyl-4-carboxylic acid, H(2)bdc = 1,4-benzenedicarboxylic acid), have been successfully synthesized under solvothermal conditions, and the crystal structures were testified by the single-crystal X-ray diffraction analysis and PXRD analysis. The photocatalysis activities of 1-5 were investigated by photodegradation of methyl orange (MO) experiments under visible light irradiation. Results indicated that 1 is nearly an inactive photocatalyst for degradation of MO, whereas 5 exhibits excellent photocatalytic activity under visible light irradiation. Interestingly, when Co2+ ions are gradually replaced by Zn2+ ions in the metal organic frameworks, photocatalytic activities of which have improved gradually from 1 to 5; this offers a controllable regulation of photocatalytic properties by changing metal ions in isostructural metal-doped MOFs.