A 5-DOF air-float motion simulator comprises a translation platform and an attitude platform. The translation platform comprises a ball surface air-float bearing, a rollover-preventing mechanical stop device, an elevating column, a first air pressure pipeline, a first controller, three plane air-float bearings, a translation platform installation panel, and a translation platform lithium battery. The attitude platform comprises an attitude platform installation panel, 2N air bottles, a second air pressure pipeline, an iGPS, four cold air nozzle, an inertial navigation system, a second controller, three fly wheels, a center of mass adjustment system, and an attitude platform lithium battery. The translation platform accomplishes translation movement in the X and Y directions, the attitude platform accomplishes rotation with respect to the pitch axis, roll axis and yaw axis, so that the simulator achieves simulation of spatial attitude rotation and track translation movement of a spacecraft.