The application of fractal porous media (FPM) theory in melt crystallization is a novel concept to be developed extensively, which has received wide attention in recent years. The primary advantage of FPM theory is the ability to describe the complex, random structure of porous crystal layers with fewer parameters. This review will introduce aspects of the property analysis of porous crystal layers grown in the heterogeneous thermal field. For the first time, the existing flow model of FPM theory will be outlined and an overview of the general issues, model modification, and validation of the separation process in melt crystallization will be discussed in detail. Kinetic and model research on separation evaluation and optimized operation will be mentioned to unfold the promising application field. Finally, the paper will conclude with perspectives on the future research directions, key challenges, and issues in this area.