Abstract: In order to study the 3-D features of Cr atoms in laser cooling field,the interaction process of Cr atom and laser cooling field was analyzed.Based on the semi-classical theory of Doppler and polarization gradient force,the fourth-order Runge-Kutta algorithm was adopted to simulate 3-D trajectory of Cr atoms,at the same time,three-dimension distribution of them was also obtained.After passing through laser cooling field,the divergence angle of Cr atomic beam becomes smaller,and the corresponding velocity also decreases.The results show that the three-dimension features of Cr atoms agree with the two-dimension cases,and can provide more comprehensive,richer cooling information.