本发明公开了一种制备乙酰乙酸甲酯的方法,一次加入催化剂,双乙烯酮和甲醇溶液由原料进料口连续加入,萃取剂由萃取剂进料口连续加入,两股物料同时加入反应萃取精馏塔中,开始加热;全回流,反应萃取精馏塔塔顶可获得甲醇溶液,反应萃取精馏塔塔釜为乙酰乙酸甲酯、催化剂及萃取剂的混合液,混合液经由塔底出料口流入减压抽提塔中,减压抽提塔塔顶得到目标产物乙酰乙酸甲酯。通过设 The invention discloses a method for preparing methyl acetoacetate. The catalyst is added in one time, the diketene and the methanol solution are continuously added from the feed inlet of the raw material, the extractant is continuously fed from the feed inlet of the extractant, and both materials are simultaneously added to the reaction extractive distillation Tower, start heating; full reflux, the reaction extract distillation column overhead methanol solution can be obtained, the reaction extraction distillation column reactor acetylacetate, catalyst and extractant mixture, the mixture through the bottom discharge port Into the vacuum extraction tower, vacuum distillation tower top to obtain the target product methyl acetoacetate. By setting