A digital video target moving object segmentation method and system is designed for processing a digital video stream for segmentation of every target moving object that appears in the video content. The proposed method and system is characterized by the operations of a multiple background imagery extraction process and a background imagery updating process for extracting characteristic background imagery whose content includes the motional background objects in addition to the static background scenes; and wherein the multiple background imagery extraction process is based on a background difference threshold comparison method, while the background imagery updating process is based on a background-matching and weight-counting method. This feature allows an object mask to be defined based on the characteristic background imagery, which can mask both the motional background objects as well as the static background scenes.