Deflection nose is a new concept of fast response control mode, partial nose of projectile can deflect certain angle relative to the axis of projectile body and pressure difference emerges in the windward and leeward side of warhead then generates aerodynamic control force, and this control way has high control efficiency and very good application prospect in the ammunition system. Nose deflection actuator based on smart material and structure makes projectile body morphing then obtains additional aerodynamic force and moment, changes the aerodynamic characteristics in the projectile flight process, produces the corresponding balance angle, sideslip angle then resulting in motor overload, adjusts flight moving posture and controls the ballistics, finally realizes shooting range changing and improves firing accuracy. In order to study characteristics of self-adaptive control projectile, numerical simulations were conducted by fluid dynamics software ANSYS FLUENT for fin stabilized rocket projectile. Computed aerodynamics on different nose delectation angle, different Mach number and different angle of attack, and compared the aerodynamic characteristics with the different nose deflection angles. Results show that the nose deflection control has bigger influence on the head of rocket projectile, and caused asymmetry of the flow field structure, make the warhead differential pressure in the windward and leeward surface increases, resulting in a larger lift. Finally, ballistics experiments were done for verification. Results can offer theoretical basis for self-adaptive rocket projectile design and optimization also provides new ideas and methods for field smart ammunition research.