The utility model relates to a collecting bag, especially a collecting bag which can be directly connected to the anus of a pet to collect excrement. The bag is mainly composed of a flexible bag body, the upper end is provided with a set of connecting sections, the connecting section is led through the inner part by a through mouth, the lower end is a back cover, and the two parts are connected with a deformation body section. Before use, the bag body can be integrated into a stack shape, and the connecting section is connected to the pet organ. After the process of accepting the excrement body, the bag body can Deformation enlarges the internal volume, and afterwards the opening can be bunched.一種集便袋，尤指可直接於寵物肛門以封接式集收便體之集便袋，主要係由一可撓性變形的袋體，上端設有一套接段，套接段由一通口導通內部，下端為一封底，二者跨接有變形身段，使用前為可整收成疊置狀，套接段套接於寵物器官，承接便體的過程後，袋體可變形擴大內容積，及事後通口可被整束。
