The invention discloses an aerospace vehicle combined navigation robust filtering method based on a launching inertia coordinate system, belonging to the technical field of air vehicle combined navigation. The aerospace vehicle combined navigation robust filtering method comprises the following steps of performing inertial navigation algorithm arrangement by taking the launching inertia coordinate system as a reference coordinate system, and constructing a position, speed and posture calculation model of an air vehicle under the launching inertia coordinate system; on the basis of the position, speed and posture calculation model, constructing an equation of navigation system error states including a basic navigation parameter error and an inertia instrument error, and obtaining a posture linear measurement equation through a conversion module according to original star sensor measurement information; and finally estimating and correcting all state values in the constructed state equation by the robust filtering method. According to the aerospace vehicle combined navigation robust filtering method disclosed by the invention, the influence, caused by a geophysical field, on the navigation system of the air vehicle can be effectively reduced; furthermore, under a condition that the navigation system model of the air vehicle is inaccurate, a filter can work stably; therefore, the precision of a combined navigation system is improved.