Abstract: To confirm the optimization design for vision display interface of a plane cockpit in the design phase, the comprehensive evaluation of mental workload has been used. Colligating the three mental workload evaluation methods, which are main task evaluation method, physiology measure method and subjective evaluation method, the model of plane cockpit vision display interface mental workload comprehensive evaluation has been founded, the most optimized design has been selected and has been testified by an experiment. In some type plane vision interface different designs, their mental workload evaluation values were gained using the model on the landing task. The design of the mental workload value was the best one, also tallied with the design theory of vision interface in nation military criterion. During the phases of plane cockpit vision interface design, this comprehensive evaluation system could get a satisfying evaluation result. It could be helpful for the final determination of the designing scheme.