Semi-solid processing technology is an important method for metal casting, products processed using semi-solid processing technology have advantages such as small solidification shrinkage, high dimensional accuracy of castings, fast forming speed, high productivity, and good mechanical properties. Aluminum alloy products produced by semi-solid forming can undergo heat treatment, and the mechanical properties of the products after heat treatment are similar to those of steel, but they have a lighter weight than steel and are widely used in many fields. Semi-solid slurry preparation technology is one of the key technologies in aluminum alloy semi-solid forming, which determines the industrial application of semi-solid forming and also has a significant impact on the quality of aluminum alloy products formed by semi-solid processes. With the continuous development of semi-solid pulping technology, the semi-solid processing technology of metal materials has become an emerging technology in the field of metal product processing. This article reviews the principles and characteristics of various semi-solid slurry preparation technologies for metal materials, the advantages and disadvantages of various methods for preparing semi-solid slurry are compared and analyzed, and explores the future trends of semi-solid slurry preparation technologies.