Hexaaquaaluminum methanesulfonate crystals, [Al(H2O)6][CH3SO3]3 were synthesized by hydrothermal reaction of Al(OH)3 with methansulfonic acid. Heating at 265 ℃ for 5 h, (Al2(OH)(CH3SO3)5) was gotten. The six-coordinated enviroment of the central Al atom is also determined by Elemental Analysis, Chemical titration and 27Al MAS NMR measurement. Thermogravimetric and Fourier transform infrared analysis show that the decomposition intermediate product at 265-365 癈 is Al2(OH)(CH3SO3)5 and the final product is amorphous Al2O3 residue with about 0.8 wt% SO3. Tetrahydropyranylation of n-butanol at room temperature in dichloromethane, catalyzed by Al2(OH)(CH3SO3)5 got 100% yielding. After compared, Al2(OH)(MS)5 exhibits the highest catalytic activity (100% yield) among various aluminum salts. Furthermore, Al2(OH)(CH3SO3)5 can be recycled, which enable to be environmentally benign and economical candidates for similar catalytic reactions.