The utility model provides a slurry pressure rising device for high pressure slurry homogenizing devices. The utility model is composed of a high pressure pump, a thick slurry pump, a high pressure material tank, a pipeline, a valve, an injecting crushing device, etc. The utility model is characterized in that a partition plate which is automatically positioned between clear liquid and material slurry is arranged in the high pressure material tank and moves along the liquid surface; the clear liquid and the material slurry respectively enter and exit from the upper and the lower inlets and outlets of the high pressure material tank. The waste liquid has little mixing material, and the utility model avoids the defects of raw material wasting, material slurry concentration reduction, etc., and is favorable for dewatering and repetitively crushing. The utility model is provided with two high pressure material tanks which alternatively work, the slurry entering and the waste liquid discharging are carried out in synchronism, the auxiliary time is shortened, and the crushing efficiency improves about 30%.