Abstract: Polyimide (PI) is widely used in low Earth orbit (LEO) spacecraft, but is vulnerable to atomic oxygen (AO) erosion. To address this issue, PI was blended with 5 wt% of Ti₃C₂T_x nanoparticles and Ti₃C₂T_x/PI composite films were prepared using continuous centrifugal spraying technology. The AO erosion resistance of the films was evaluated under a simulated LEO environment with a flux of 1.2×10¹⁶ atoms/(cm²·s) and energies between 5-10 eV. The results showed that the composite films maintained the original mechanical properties of PI films while exhibiting significantly improved AO resistance, with an AO erosion yield of only 6.6% that of the PI films. These findings, confirmed by both experimental and molecular dynamics simulation, revealed that Ti₃C₂T_x reacts with AO to form a titanium oxide passivation layer, effectively protecting the material from further AO attack. The results demonstrate the potential of Ti₃C₂T_x/PI composite films as novel high-performance anti-AO erosion materials for LEO spacecraft applications.