The invention discloses an air floating simulator posture platform assistant leveling and platform body support device, and relates to the field of aircraft space posture movement simulation. The air floating simulator posture platform assistant leveling and platform body support device comprises a posture platform, a lifting device, a support device, a translation platform and universal castors, wherein the translation platform is arranged at the lowermost end; the lifting device is vertically and fixedly mounted in the center of the upper surface of the translation platform; the posture platform is fixedly mounted at the upper end of the lifting device; the support device is arranged around the lifting device and the translation platform; the top end of the support device is in contact with the lower surface of the posture platform; the universal castors are fixedly mounted at the bottom end of the support device. By adopting the air floating simulator posture platform assistant leveling and platform body support device, the posture platform and the translation platform of an air floating simulator can be conveniently and rapidly separated in a physical manner, so that a spherical surface air floating bearing is released from load and stops working. Meanwhile, the air floating simulator posture platform assistant leveling and platform body support device is used for testing the mass characteristics of an air floating simulator posture platform, used for calculating a three-dimensional compound pendulum cycle of the posture platform, and used for assisting leveling operation of the air floating simulator posture platform.