Energy centroid algorithm is mostly used in center location of light spot, which is effected by the intensity distribution distortion of received light spot compared with that of light source. A distortion model is constructed, and a correcting factor is introduced. The related correcting algorithm is proposed, which modifies the conventional centroid algorithm. The correcting process applied in satellite laser communication is described. Computer simulation verifies that, under some factual circumstance, the angle deviations resulting from neglecting the asymmetrical attenuation of laser illumination can exceed 109″. Therefore, in satellite laser communication, correcting factor introduced improves the locating and tracking precision and the channel reliability.