Aiming at the problem of overstock and waste of maintenance materials, the inventory of maintenance materials for aerospace TT&C (tracking, telemetry and command) equipment is optimized. Referring to the existing research results of multi-level inventory optimization, the improved particle swarm optimization algorithm is used to describe the inventory optimization process of maintenance equipment of TT&C equipment as follows: when the availability of TT&C equipment reaches the specified level, considering 2 maintenance strategies of non string repair and string repair, constructs the inventory optimization model of maintenance equipment based on the constraints of equipment availability and equipment support cost. The optimal carrying operation scheme of maintenance equipment of TT&C equipment is acquired and verified by an example. The results show that the model and optimization algorithm are trusted, and has great application value.