The utility model discloses an emulsion collecting vat from belt cleaning device, including cell body, tank bottom, accuse liquid sulculus, elevator pump mouth, drain, 20~60 mils in the bottom of cell body is personally submitted with the level to the tank bottom, controls the liquid sulculus in the lower extreme port department connection of tank bottom, is equipped with elevator pump mouth and drain at the side of controlling the liquid sulculus. The utility model discloses an improve the structural style and the loop structure of collecting vat to realizing the automatic best effect of washing the collecting vat bottom of rolling mill emulsion, making at the bottom of the collecting vat not deposit fatlute, just do not need regular cleaning cell so on the one hand, alleviate workman's intensity of labour, on the other hand reduces the economic loss that cleaning cell caused, and the most important is the clean nature that keeps the emulsion, thereby ensures that the high quality surface requires the production of board.