Abstract: The paper depicts a software assessment system, Dynamic Interaction Analysis Support(DIAS), based on computer simulation technology for man-machine interfaces(MMI) of a control room. It employs a computer to simulate the operation procedures of operators on man-machine interfaces in a control room, provides quantified assessment, and at the same time carries out analysis on operational error rate of operators by means of techniques for human error rate prediction. The problems of placing man-machine interfaces in a control room and of arranging instruments can be detected from simulation results.DIAS system can provide good technical supports to the design and improvement of man-machine interfaces of the main control room of a (nuclear) power plant.