Abstract: In order to study the effect of external stimulus duration on the emotional state transition of people,firstly,the Gross emotional regulation process and the finite state machine are used to describe the emotional state transition process. Then the emotional enhancement factor is introduced according to different stimulus durations. The external stimulus duration is associated with the state transition matrix to determine its effect on the emotional state transition. Finally,simulation analysis was done for the proposed algorithm. The results show that the impact of external stimulation on the emotional state transition will be bigger with the increase of stimulus duration,but the rate of increase slows down gradually. The algorithm can effectively describe the relationship between the stimulus duration and emotional state transition matrix.