The invention provides a back-pumping type filling machine comprising a filling support and a conveyor belt support. The conveyor belt support is arranged under the filling support, the filling support comprises a fixing frame, a movable frame arranged on the fixing frame, and a bottle clamping frame. A filling head comprises a feeding pipe, a feed pumping pipe, a feed pumping opening of the feeding pipe, and a feed pumping opening of the feed pumping pipe. The upper end of the filling head is provided with a feeding opening which is communicated with the feeding pipe, the outside of the feeding pipe is sleeved with the feed pumping pipe, and length of the feeding pipe is greater than the length of the feed pumping pipe. The feed pumping opening of the feeding pipe and the feeding pipe arevertically disposed and are communicated with each other, and the feed pumping opening of the feed pumping pipe and the feed pumping pipe are vertically disposed and are communicated with each other.The back-pumping type filling machine adopts a back-pumping type filling mode, compared with a traditional negative-pressure type filling mode, a sealed head is not required to be set up, the fillinghead is not required to touch a bottle opening, thereby reducing the pollution of the bottle opening, and cleanliness of the filling is ensured.