Abstract: The effects of in-situ hydrothermal treatment on the ZSM-5 zeolite were studied, and its performance for syngas to gasoline via DME reaction process was dicussed using two-stage equal-pressure reactor system. The texture, surface acidity and catalytic performance of the treated ZSM-5 zeolite at different temperatures were investigated. Physicochemical properties of the zeolite were characterized by XRD, XRF, BET, NH₃-TPD and TPO. The results indicated that most of Al was removed from the nonframework of zeolite through appropriate hydrothermal treatment at 400℃. A decrease in the amount of acidic sites and an increase of specific surface area were observed, and accordingly, the catalytic activity of the ZSM-5 zeolite and product selectivity were improved significantly.