Molecular distillation combines the film formation characteristics of film evaporation or molecular distillation with high vacuum sealing methods, integrating the distillation function to form a system that not only inherits the advantages of both film evaporation and molecular distillation equipment—high vacuum levels and short heating times—but also overcomes the limitations of insufficiently high purity in the separation process. This achieves multi-functional capabilities in one unit, especially exhibiting unique advantages in the handling of thermally sensitive materials.