Abstract: The HRV(Heart Rate Variability) data of ship navigators in different navigation situations are collected through simulation experiments on a marine simulator.The model of Navigator’s psychological load based on factor analysis is built and the psychological load characteristics of navigators on duty are analyzed.The research shows that, for calculating navigator’s psychological load, heart rate variability is more efficient and more reliable than heart rate.The calculation shows that for a voyage, the psychological load goes up at the beginning, then, gradually goes down and keeps lower level as the voyage proceeds and the navigator gets used to his duty.During last stage of a voyage, the psychological load keeps low and changes smoothly.Unexpected Incidents will cause obvious increase of psychological load.