The use of field survey data, according to the characteristics of packet statistics, conformation of hierarchy, marks of hierarchy, solidified hierarchy are used to identify the existence of internal labor markets, and the find is that wage is attached to hierarchy. The hierarchy is an important basis for the resources allocation of SMEs in manufacturing enterprises. There’s positive relationship between the hierarchy and stability willingness of migrant workers. Thus, the establishing of internal labor markets could increase the stability of migrant workers in occupations. And the combination of internal and external labor market will help to improve the autonomy and flexibility of two-way choice between enterprises and migrant workers, and establish a stable employment relationship.