A preparation method of hydroxyethyl (meth)acrylate adopts a three-segment tubular reactor and tower reactor combination technology, and concretely comprises the following steps: mixing a catalyst, a polymerization inhibitor and (methyl)acrylic acid until solids are dissolved, mixing the above obtained solution with parts of ethylene oxide, allowing the obtained mixture to enter a first tubular reactor and to react, mixing a reaction solution flowing out of the first tubular reactor with a certain amount of ethylene oxide, allowing the mixed reaction solution to enter a second tubular reactor and to react, mixing a reaction solution flowing out of the second tubular reactor with a certain amount of ethylene oxide, allowing the obtained reaction solution to enter a third tubular reactor, allowing a reaction solution flowing out of the third tubular reactor to go through a heat insulation tower reactor in order to carry out ageing, and extracting to obtain a product liquid. The method has the advantages of obvious improvement of the reaction efficiency, further improvement of the product yield, reduction of generation of diester, monoester and other impurities in side reactions, realization of continuous production, and reduction of the operation risk of an apparatus.