An effective procedure for the synthesis of alpha-hydroxyphenylacetic acid with cyclodextrin (CD) catalysts was developed. The phase-transfer catalyst types, catalyst loadings, reaction times, reaction temperatures, and substrate molar ratios were investigated to optimize the reaction conditions. In addition, the factors that affect the reaction were studied, and the relationship between benzaldehyde and beta-cyclodextrin (beta-CD) was analyzed through 2D-ROESY. The equilibrium constant when beta-CD was used as the catalyst was calculated. The results indicated that beta-CD is the optimal catalyst for the reported reaction (yield: 69.08%). Furthermore, the mechanism underlying the reported reaction was proposed.