Based on China National Monitoring Survey of Migrant Population 2013, that was conducted by National Health and Family Planning Commission, the psychometrics indexes of Social Integration Scale of Migrant Population were analyzed. 4 items of the scale was deleted according to the discrimination and meaning, and the structure of the scale was modified. The items of the modified scale showed satisfying discrimination, and reliabilities of the scale and sub-scale were quiet good. The close relationship between social integration and future living willingness, Identity of city, and hukou transferring willingness were found. This also suggested that Social Integration Scale of Migrant Population should be used correctly.