The dynamic characteristics of deflectable nose missiles with rotary single-channel control were investigated in this paper. Firstly, the effective angle of attack, effective angle of sideslip and quasi-body coordinates were introduced based on the spin characteristics of the missile’s body. Secondly, considering the interaction between the missile’s nose and body, the rigid kinetic model of missile with deflectable nose control was set up in the quasi-body coordinates utilizing rootless multi-rigid-body system dynamics. Finally, computer simulation was performed to investigate and analyze the interaction between the missile’s nose and body. Academic analysis and simulation results indicate that the nose deflection will cause a motion of body on the opposite direction, and the kinetic model established in this paper is correct and reasonable.