When simulating or designing plate heat exchangers for multicomponent mixtures, most de-signers are often perplexed with the question on how to choose or estimate the physical property param-eters and hope to have a reliable database that could be adopted. The commercial codes HYSYS supply the physical property package on over 1500 pure substances and over 16 000 binary coefficients for them.This work has briefly presented an efficient communication interface based on the Microsoft Component Object Model (COM) between inner plate heat exchanger simulation codes and the HYSYS package. The application of a custom-made HYSYS-COM interface has shown high efficiency, such as significant re-duction of time needed for evaluating each process stream’s properties. This automation method can be conveniently extended to further optimization study for any specific operation device such as heat transfers,columns, and other facilities.