The chief aim of the present study is to find the effect of the nose motion upon the main body of the deflectable nose missile. The dynamic model including the motions of the nose and main body is built. The dynamic simulation and analysis show the interferential moment of the nose and main body can cause disadvantageous “body flutter”. The coupling motions can be decreased through lightening the weight of the nose. The coupling motion can be decreased greatly when the point of hinge、mass center the nose are set on one place. The roll increases the motion coupling of the three channels of the missile.