Abstract: In order to improve the accuracy of directional detection with the same number of optical channels in the fiber-array laser receiving antenna,a new directional detection algorithm was been proposed,in which the two-dimension waveform data of time delay was expanded into three-dimension data,and the angles were calculated based on the matrix of echoed laser intensity,and the suppression of false alarm was also considered.Comparing the angular resolution with this algorithm before and after,its absolute accuracy was improved significantly from 5° to 2°.It is seen that this algorithm can obviously improve the accuracy of directional detection.