The classic sled-type landing gear makes it challenging to take off and land in challenging terrain, with the widespread usage of rotorcraft UAVs in both civil and military domains. This research develops a two-stage buffered adaptive landing gear that is similar to a human leg in order to increase the landing area and application range of rotorcraft UAVs. An adaptive landing gear attitude adjustment strategy was proposed after researching the positive and negative kinematics of the bionic leg. A bionic quadruped hexacopter UAV landing dynamics model was established, landing dynamics simulation was carried out using the multi-body dynamics software simcenter 3D, and a comparison of landing performance with the conventional sled landing gear was carried out. The research demonstrates that the two-stage cushioned adaptive landing gear in the landing leg style and its attitude adjustment strategy can reduce roll angle by 95.69% and overload coefficient by 34.06%, proving that the two-stage cushion adaptive landing gear has excellent shock absorption and cushioning capability in the face of complex terrain.