The utility model relates to a material blending machine, in particular to a negative pressure burden machine used for the mixing emulsification of the ice cream, diary products and drinks with more burdens. The utility model adopts the following technical proposal that: a negative pressure burden machine is characterized in that a vacuum pump is arranged on a frame and the vacuum pump is communicated with a burden mixing drum through a duct. A material inlet channel with a valve is arranged on the burden mixing drum. By adopting the proposal, the utility model overcomes the defects existing in the prior art and provides a novel negative pressure burden machine which has simple structure, can be put into production continuously, causes no pollution, lowers the labor intensity and enhances the emulsification fineness.