MOF-5 was synthesized by a direct mixing method at ambient temperature. Relevant treatment procedures of solvothermal activation, preservation in a solvent, and reactivation of MOF-5 under anhydrous conditions were proposed and proved efficient. In order to examine the influence of densification of MOF-5 on the methane volumetric storage capability, the practical packing densities of the samples mechanically pressed under different pressures were measured. The results indicate that mechanical pressing could improve the packing density, but decrease the methane gravimetric storage quantity to some extent. The optimized effective volumetric storage quantity of methane reached 81 V(STP)/V at 3.69 MPa for the sample pressed under 1.0 MPa.