Abstract: The present disclosure belongs to the technical field of separation and purification of glycolic acid, and in particular, to a method and device for separation and purification of glycolic acid by a rectification-crystallization coupling process and use. Bio-based platform compound molecules are used as raw materials to synthesize the glycolic acid, and the obtained crude glycolic acid is separated and purified using the rectification-crystallization coupling process to obtain high-purity glycolic acid. The method initiates system separation and purification under a new glycolic acid synthesis route, which has the difficulty that the glycolic acid is easy to polymerize during concentration, so there are technical barriers to equipment design of vacuum rectification and adjustment of process parameters. In addition, during crystallization, there are technical barriers to equipment design of a crystallization kettle and adjustment of process parameters.