Rocket body rigid-flexible coupling landing dynamics modeling method and device

The invention discloses a rigid-flexible coupled landing dynamics modeling method and device for a rocket body. The method comprises the following steps: acquiring an initial condition; establishing a recovery leg model based on recovery leg parameters, a simplified rocket body model based on rocket body parameters, a connection form model based on a model connection form, a landing ground model based on landing ground parameters and a collision module model; the step of building the recovery supporting leg model comprises building a supporting leg elastic model, building a buffer model and building a foot pad model; according to the connection form model, connecting the supporting leg elastic model with the foot pad model, the supporting leg elastic model with the buffer model, and the buffer model with the rocket body simplified model; and according to the initial conditions, connecting the foot pad model and the landing ground model through the collision module model to obtain kinetic parameters of the roc