本发明提供一种聚甲氧基二甲醚的制备方法,以工业级甲醇和甲醛溶液为原料,或以工业级甲缩醛和甲醛溶液为原料,将原料加热后从膨胀床反应器底端泵入,与催化剂接触并发生反应;反应完后从层流床反应器顶端进入,与催化剂接触并发生反应,得到粗品聚甲氧基二甲醚;将粗品聚甲氧基二甲醚分离提纯得到聚甲氧基二甲醚。本发明在工业化生 The invention provides a preparation method of polyoxymethylene dimethyl ether, which is prepared from industrial-grade methanol and formaldehyde solution or industrial-grade methylal and formaldehyde solution as raw materials, Pumped into contact with the catalyst and reacted; after the reaction enters from the top of the laminar flow bed reactor, contacts with the catalyst and reacts to obtain a crude polyoxymethylene dimethyl ether; the crude polyoxymethylene dimethyl ether is separated and purified Polymethoxy dimethyl ether was obtained. The invention is industrialized