Compared to methanol, dimethyl ether (DME) is a more ideal and attractive raw material for industrial applications. Typically, the industrially zeolite-catalyzed methanol dehydration to DME occurs at temperatures above 423 kelvin. Improving catalytic reactivity and reducing energy consumption are urgently needed but remain challenging. Here, we report an unexplored associative strategy to realize DME formation at room temperature and the generation of olefins even at 413 kelvin, which is achieved by coinjecting basic acetone to manipulate the local chemical microenvironment of the methanol reactant inside the H-ZSM-5 zeolite. The crucial role of acetone in accelerating methanol direct dehydration to DME is highlighted as the obvious destabilization effect for the adsorbed methanol cluster with strong hydrogen bonds and the subsequent traction of water during DME formation. These findings offer more insights into the rational design of reaction systems by manipulating the local surroundings to regulate catalytic performances and should represent a large step forward in methanol conversion technology.