Abstract: Based on the data of China Laborforce Dynamics Survey 2014, the influencing factors of migrant workers' willingness to stay in China were analyzed using Structural Equation Modeling. The results showed that the subjective wellbeing played an important role in the willingness of the migrant workers to stay in the city, and the social support affected the willingness of the migrant workers through the subjective wellbeing directly or indirectly. It meant that the social support had a positive effect both on the willingness to stay in the city and the subjective wellbeing of the migrant workers, and meanwhile the subjective wellbeing also had a positive effect on the willingness of the migrant workers to stay in the city, indicating the mediating function of subjective wellbeing in the positive effects of social support on the migrant workers’ willingness to stay in the city.