Taking the three first tier cities of Beijing, Shanghai and Guangzhou as an example, this paper investigates the participation of the floating population in the local basic medical insurance. The results show that the uninsured rate of the floating population in the basic medical insurance is higher than the national average, and the local basic medical insurance participation rate of the floating population with the characteristics of low income, low education, no labor contract and old age is relatively lower. This paper puts forward the countermeasures to solve the problem of migrant population participating basic medical insurance treatment in the inflow areas.