Copper p-toluenesulfonate was prepared for replacing the Bronsted acid, which has a strong corrosive and many side effects. It can be employed as the catalyst for the condensation of glycerol with benzaldehyde and reached a good result. By optimizing the process with response surface methodology, the concrete procedure was as follows. The molar ratio of benzaldehyde to glycerol was 1:1.3, the volume for petroleum ether was 1.3 times of benzaldehyde and the dosage of catalyst was 0.9mol% of benzaldehyde. The yield of benzaldehyde glycerol acetal showed the maximum conversion of 96.0%. The acetal was an isomer mixture of two kinds of substance. It observed the transformation conditions between isomers by taking toluene as solvent. The high value of cis six-member ring was separated out extensively by crystallization under low temperature (about -20°C). The purity of the product was 96.8% and isolated selectivity was 40.8%. The reaction mechanism was explored. Furthermore, the characterization of target products were analyzed by means of GM-MS,IR and 1HNMR．