With the acceleration of globalization, the social integration of foreign immigrants has become an important issue affecting social harmony and sustainable development. This study takes foreign immigrants in City A of China as its target, and based on the social integration theory, constructs an analytical framework containing four dimensions, namely human capital, support network, policy factors and social acceptance, and empirically examines the path of each factor’s influence on social integration through multiple linear regression modeling. The study used a random sampling method to conduct a questionnaire survey on foreign immigrants in City A. The results of factor analysis showed that human capital r=0.868, social acceptance r=0.826, support network r=0.717, and policy factors r=0.664 were significantly and positively related to social integration (p<0.01). Multiple regression analysis showed that duration of stay in China had the strongest contribution to cultural integration β=14.005 and social integration β=12.421 (p<0.01). Master's degree and above significantly promoted cultural β=10.551 and social integration β=12.036, while there was a negative effect of coming from developed countries on psychological integration β=-5.799, p<0.01. The analysis of differences in individual characteristics showed that the overall level of social integration of females (M=3.812) was significantly higher than that of males (M=3.534), and that the level of integration of the group of young adults between the ages of 20-29 years old was the highest (M=4.034), Asian immigrants (M=4.145) performed best due to cultural similarity, and African immigrants (M=2.945) faced significant challenges. The study verified the theoretical hypotheses and revealed that the economic factor, R² = 0.3411, has more explanatory power compared to the psychological factor, R² = 0.0403, which provides a scientific basis for policy formulation.
