In the whole process of forging, aluminum castings are easy to cause defects such as internal looseness, shrinkage porosity air outlet. After mechanical processing, the high-density components on the surface layer are removed the internal mechanism defects are exposed. When carrying out the compression sealing test for the automobile cast aluminum parts with sealing provisions, such as cylinder block, cylinder head, intake branch pipe, brake valve body, etc., the existence of defective microporous plates will cause the leakage of sealing materials lead to a lot of waste materials, this kind of defect can be found only after the hydraulic test after machining, which will lead to more serious waves of comprehensive working hours, raw materials electric energy. In order to deal with the problem of high disqualification rate of automobile aluminum castings save the castings that will be reported for the defects, certain solutions should be adopted during manufacturing. The most widely used technology is infiltration solution, that is, leakage compensation. To put it bluntly, "infiltration" means to infiltrate the infiltration agent into the microporosity of the aluminum casting under certain standards. The inspection standard of the low-pressure casting parts after dry consolidation makes the filler penetrating into the pores the inner cavity of the casting pores connect into one, plug the microporous plate, so that the parts can consider the standard production process of pressure filling, waterproof layer leakage prevention.