Elderly migrant population has continued to expand in the recent years. Based on the data from 2015 Migrant Population Dynamic Monitoring Survey in China, this paper uses Logit model and Heckman two-step method to analyze elderly migrant population’s treatment behavior, including outpatient treatment and residential treatment, and factors that influence their choice. The results showed that for minor illness, migrant old people aged more than 70, revenue from other members of the family as the main source of income，having higher average household monthly income, with hypertension or diabetes are significantly more likely to choose outpatient treatment.For those migrant old people with diseases that need residential treatment, those who think their health condition is good，retirement or pension as the main source of income are more likely to choose residential treatment.Main source of income and type of medical insurance have significant impact on elderly migrant population’s treatment behavior. Besides, elderly migrant workers, old migrant population who rely on children or pension have significantly different treatment behavior and influencing factors.