Preparation method for synthesizing methyl benzoylformate by virtue of one-pot method

The invention relates to a preparation method for synthesizing methyl benzoylformate by virtue of a one-pot method. The method comprises the following steps of: mixing benzoyl cyanide, alcohol, a catalyst and water and dropwise adding concentrated sulfuric acid, and synthesizing methyl benzoylformate by adopting the one-pot method; then, performing post-treatment to split salt and neutralize acid ester to obtain a coarse product. According to the preparation method provided by the invention, the process flow can be simplified, the production energy consumption can be reduced, and the yield can be improved, so that the quantity of wastewater in production is greatly reduced, and wastewater can be used for producing ammonium sulfate. The preparation method is an environmentally-friendly process, and the whole process is very beneficial to industrial implementation.