Activation process designed to remove the solvent and unreacted ligands is the key step for the synthesis of metal-organic frameworks (MOFs). MIL-53(Al), a subclass of MOFs, was prepared using various synthesis and activation methods. Especially, a combined activation method was proposed. The performance of activation methods was evaluated by the specific surface area of the samples. The mechanism of activation methods was confirmed by the loading induced structural transition of MIL-53(Al) using X-ray diffraction. MIL-53(Al) activated by the combined method has the best performance and the adsorption capacities of vaporous dichloromethane (CH2Cl2) and trichlormethane (CHCl3) on this sample was investigated at 298 K and 101 kPa. The results of adsorption experiment show that MIL-53(Al) has larger adsorption capacity in CH2Cl2 than CHCl3, which is consistent with the conclusion of molecular simulation (Grand Canonical Monte Carlo).