By means of water as an extractant, the two-feed and three-feed reactive distillation production processes of methylal are synthesized and analyzed. The effects of water on the methylal reactive distillation (RD) production is investigated. Thermally coupled two-feed and three-feed reactive dividing-wall columns are proposed and analyzed. The two-feed and three-feed RD processes are compared. The three-feed thermally coupled reactive dividing-wall column (DWC) exhibits an outstanding ability of energy and cost savings. Results from this work could be helpful for further development and application of RD or reactive DWC in methylal production.