  Quantum key distribution (QKD) employed orbital angular momentum (OAM) for
encoding enhances the system security and information capacity between two
communication parties. However, such advantages significantly degrade because
of the fragility of OAM states in atmospheric turbulence. Unlike previous
researches, we first illustrate the performance degradation of OAM-based QKD by
infinite long phase screen (ILPS), which offers a feasible way for dynamically
correcting realistic turbulence through adaptive optics (AO). Secondly,
considering the failure of AO while encountering the branch cuts, we evaluate
the quality enhancement of OAM-based QKD under moderate turbulent conditions by
AO after implementing the wrapped cuts elimination. Finally, we demonstrate
that in a realistic environment, real-time AO can still mitigate the impact of
atmospheric turbulence on OAM-based QKD even in the high wind velocity regime.
