The invention provides a method for numerical computation of an aeroelastic dynamic response of a foldable cabin door of a buried-in weapon cabin based on a Newmark method. The method is characterized in that the dynamic response of the foldable cabin door during opening and closing of the buried-in weapon cabin is deemed as overlaying of two parts including rigid body displacement caused by cabin door mechanism motion driven by a motor, and elastic deformation of the cabin door structure generated under aerodynamic force effects. The method is characterized in that a piston theory is taken as an aerodynamic model in aeroelasticity analysis; a pneumatic stiffness matrix and a pneumatic damping matrix are used to describe aerodynamic force; motion principles of a four-connecting rod mechanism are used to analyze motion rules of the cabin door mechanism; then, the pneumatic stiffness matrix and the pneumatic damping matrix are amended, so that influences of the rigid body motion of the cabin door on the aerodynamic force can be computed; and according to the Newmark method, numerical solution can be carried out to an aeroelastic dynamic equation of the cabin door structure. The method has the advantages that the influences of the rigid body motion of the cabin door on the aerodynamic force during the opening dynamic course and the closing dynamic course of the weapon cabin are considered; analysis of the aeroelastic dynamic response of the foldable cabin door becomes more accurate; and a new idea is provided for the numerical computation of the aeroelastic dynamic response of the foldable cabin door.