Four CuZnAl slurry catalysts with different contents of Al were directly prepared from the solution of these metal salts to catalyst slurry by a complete liquid-phase method. The structure properties of the catalysts were characterized by XRD, BET, XPS, FTIR, and their catalytic performances for the single-step synthesis of Dimethyl ether (DME) from syngas were evaluated in a slurry reactor of 250 mL with a mechanical magnetic agitator. The results indicate the main phase existed in the catalysts are Cu, Cu2O, ZnO and boehmite (AlOOH) and the structures of pore and surface are comparable with those of the commercial methanol synthesis catalysts. Activity tests show that the slurry catalysts are quite effective for the single-step synthesis of DME from syngas. Among them, the catalyst with 2.09 mol% Al is best, whose DME selectivity reaches 93.08%. All of the catalysts prepared by the novel method exhibit good stability during the reaction time investigated for 18 days.