By analyzing the basic theory of CA and improving the algorithm of occupant psychology, we simplify the complex algorithm of Euclid space distance, which reflect the occupant psychology of crowds and improve the quality efficiency of the rejection of dangers and the appealing of the exits. This paper mainly studies the effect of the density of crowds, the width of the exits, the occupant psychology of the crowds. The results show that the evacuation time grows linearly with the amount of the crowds, and decreases in negative exponent with the width of the exits. Follow the crowds blindly will cause congestion because the low efficiency of evacuation.