To evaluate the dynamics of the coupled medium-low-speed maglev train-turnout system, a rigid-flexible dynamics model of the coupled system was developed based on multi-body dynamics theory and finite element method. The modal and dynamic responses results obtained from the model calculations were compared with the field test results, and the dynamic interaction characteristics of the coupled system under different operating conditions were investigated using the validated simulation model. Research results show that both the increase in the support stiffness of the turnout and the rational choice of some key parameters of the coupled system will ensure the levitation stability of the train. Increasing the support stiffness of the turnout by means of adding a trolley to support in the middle of the long-span girder (LSG) facilitates the stable levitation of the train when standing still above the turnout and improves the dynamic performance of the coupled system. By optimising some key parameters, including limiting the flatness of the magnetic pole surface of the turnout track within 1.5 mm, and taking the vertical damping of the air springs for overloaded train within 9000∼11,000 N·s/m, significant improvements in the dynamic performance of the train and the turnout can also be achieved.