To overcome the shortcomes of large energy distraction, slow detection speed and low detection probability in target detection using the technique of energy accumulation based on traditional Dynamic Programming Algorithm (DPA), an energy accumulation method of IR point target detection based on DPA is proposed.The Weighted Information Entropy (WIE) attenuation factor and directional weights are imported into the DPA recursive formula.Research results indicate that the WIE can reflect the targets’ moving information.When a target exists in the searching window, accumulated energy shows a little attenution, which guarantees the larger energy accumulation and less energy distraction in the area of target track.Moreover,directional weights can reflect the moving direction of a target and make the energy accumulation toward the moving direction with a large probability.An experiment is carried out for 12 frames of image sequences with the average SNR of 2.172 5.Results show that the accumulated energy reaches the detecting threshold in the 5th frame with the detection probability of 0.915 by using the proposed method, while the energy reaches the threshold in the 9th frame with the detection probability of 0.956 by using the traditional method.It is concluded that the method is able to reduce the area of energy distraction tremendously and can increase the detecting probability and speed obviously.