The internal thermally coupled distillation column (ITCDIC) is a frontier in the energy-saving distillation research. The process inside a high-purity ITCDIC is of great nonlinear dynamics, high sensitivity to disturbances and inverse response, which prevent the process from being commercialised. To obtain a satisfactory control performance, a dynamic matrix control (DMC) is presented. The benzene/toluene system is studied as a simulation example. The results are compared with a traditional PID and an adaptive multivariable generalised predictive control (AM-GPC) in detail. The performances in both servo and regulatory control confirm the accuracy and validity of the DMC for the high-purity ITCDIC process.