By employing the H3PMo12O40 to assemble metal-organic framework((Cu3(BTC)2, BTC=1,3,5-benzenetricarboxylate), a metal organic frameworks composites, namely {H3PMo12O40@Cu3(BTC)2}?xG (G＝guest). Through X-ray powder diffraction pattern (XRD), Fourier transform infrared spectrum (FT-IR), scanning electron micrographs (SEM), thermogravimetric (TG), brunaue Emmett teller (BET) H3PMo12O40@Cu3(BTC)2 the composition, structure, morphology, stability and toleration of H3PMo12O40@Cu3(BTC)2 have been fully characterized. The adsorption of methylene blue onto H3PMo12O40@Cu3(BTC)2 in aqueous solution was studied. The effects of the experimental parameters, including sample solution initial pH, temperature and initial concentration have been investigated. The results showed that the lower temperature and lower initial pH value were beneficial to the dye adsorption. The experiment data could be well described by the Langmuir equations and pseudo-second-order kinetic model. Thermodynamic parameters ΔG<0，ΔΗ<0 and ΔS>0 indicated that the MB adsorption onto H3PMo12O40@Cu3(BTC)2 was spontaneous and endothermic, The adsorption towards methyl violet, rhodamine B, malachite green and basic fuchsine cationic dyes also showed good adsorption properties.