Dynamic simulation is a powerful tool for chemical process optimizing design, which gives an intuitionistic sight for engineer to understand chemical process and analyzing process design. In this work, a dynamic simulation model for the full flow isopropyl benzene plant is presented. The dynamic model is based on detailed configuration of equipment data from a 300,000 t/a isopropyl benzene plant. It was discovered that the benzene column has the problem of pressure fluctuation. The cause of this fluctuation was analysed and the solutions to solve problem were presented by using dynamic model. Emergency condition, and partial power failure, both were considered for isopropyl benzene column design. The dynamic relieving rate was calculated, and the results compared with that calculated from conventional method. In order to avoiding the relieving rate, high integrated protective system (HIPPS) was applied to the dynamic model. The results shown that (1) The reason of benzene column pressure fluctuation is that the solubility of propane in condensate is sensitive to process parameters. A pressure control scheme with tuned PID parameters was proved in good performance; (2) The relieving rate of isopropyl benzene column calculated from dynamic model decrease 65% compared with that of conventional method; (3) The relieving rate of isopropyl benzene column was cut to zero by using HIPPS.