Abstract: Based on the dynamic monitoring survey data of the national floating population in 2017, the impact of social isolation on the residence intention of the elderly floating population was analyzed. First of all, the application of binary Logistic regression showed that social isolation has a negative impact on the residence intention of the elderly floating population, and the control variables such as age, education level, registered residence nature, job, self-purchased house, mobility scope and mobility time also affected the residence intention of the elderly floating population. Secondly, the propensity score matching method was used for robustness test, which further proved that the negative impact of social isolation on the residence intention of the elderly floating population was stable. Finally, the paper discussed the influence mechanism of the intermediary variable of the sense of urban belonging between social isolation and residence intention. In order to improve the residence intention of the elderly floating population, the following suggestions were put forward: expanding the social network of the elderly floating population so as to reduce the occurrence of social isolation, paying attention to the registered residence and housing needs of the elderly floating population to provide equal opportunities and security, along with improving the sense of urban belonging of the elderly floating population for achieving subjective identity.