An　adaptive　H-infinity　decentralized　fault-tolerant　control　algorithm　is　proposed　for　a　free-floating　space　robot　under　partial　loss　of　actuator　effectiveness.The　dynamics　equation　of　the　space　robot　is　established　by　the　use　of　Lagrange　method.The　system　is　decentralized　into　several　subsystems　based　on　the　idea　of　decentralization　and　the　effective　factor　representing　the　control　ability　of　the　actuator　is　integrated　into　each　subsystem.The　actuator　failure　of　a　subsystem　will　not　affect　the　normal　operation　of　the　adjacent　actuator.The　fault-tolerant　control　of　the　whole　system　is　realized　by　designing　unified　fault-tolerant　algorithm　for　each　subsystem.Simulation　results　show　that　the　algorithm　has　a　higher　tracking　speed　and　higher　tracking　accuracy　compared　with　the　existing　non-singular　terminal　sliding　mode　fault-tolerant　algorithm.　©　2019,　Editorial　Office　of　Chinese　Journal　of　Computational　Mechanics.　All　right　reserved.