The invention provides a preparation technology and a preparation device of 3,3-dimethylbutyraldehyde. The preparation technology comprises the following steps: 2-chloro-2-methylpropane and vinyl acetate react under the conditions that dichloromethane is taken as a solvent and aluminum chloride is taken as a catalyst, and a first reaction product containing 1-chloro-3,3-dimethylbutyl acetate is obtained; the first reaction product and water are mixed and input into a thermal fluid passage of a plate heat exchanger, a cooling agent is input into a cold fluid passage of the plate heat exchanger, the first reaction product and the cooling agent are enabled to exchange heat in the plate heat exchanger in a first downstream heat exchange process manner and in a second upstream heat exchange process manner, so that the first reaction product has continuous hydrolysis reaction, and a second reaction product containing 3,3-dimethylbutyraldehyde is obtained; the second reaction product is subjected to distillation separation, and the target product 3,3-dimethylbutyraldehyde is obtained. According to the preparation technology provided by the embodiment of the invention, continuous production can be realized, and the production efficiency is increased.