The invention discloses an adapter mechanism, comprising a case, a base plate, an interface, electric bolt holes and a position-fixing mechanism, wherein the case is a hollow structure which is provided with an opening at one end; the base plate is arranged at the opening of the case; the case and the base plate form an intelligent
insertion plate main body; a storage space is arranged in the intelligent
insertion plate main body; the interface is arranged on the base plate; the electric bolt holes are arranged on the base plate; and the position-fixing mechanism is arranged on the base plate.Compared with the prior art, the adapter mechanism solves the problem that a single
machine module is generally assembled onto a
satellite platform only on the ground and can not be directly assembled onto a
satellite through on-
orbit insertion and extraction due to the complicated mechanical, electrical and thermal connection relation between the single
machine module and the
satellite. The adapter mechanism for on-
orbit replacement of the single
machine module provided by the invention changes an on-
orbit replacement problem of the single machine module into a replacement problem of a combination of the adapter mechanism and the healthy single machine module, thereby avoiding the on-orbit direct
assembly of the single machine module and facilitating the
engineering implementation of theon-orbit replacement of the single machine module.