It is a common phenomenon in labor migration that a large proportion of the labor force now flows into large and medium-size cities. As one of the most important cities in China's economic construction, Shanghai is a good subject for the study of labor migration. A three-stage research on labor migration in the field of economics has been conducted to establish a labor migration model for first-tier cities. When applying the Probit regression method from the dimension of individual characteristics, family characteristics and the characteristics of the inflow cities/provinces, a conclusion can be drawn as follows: education, nationality, foreign language ability, personal income, number of family members and household consumption all have a significant impact on labor migration decision-making. It is of great significance to the reasonable transfer of labor force within the whole society and the optimal allocation of labor force resources when much attention is paid to the difference between the individual characteristics, family characteristics and the characteristics of the inflow cities/provinces.