In this study, a numerical simulation is conducted using the improved delayed detached eddy simulation (IDDES) method, the dual time-stepping LU-SGS method, and the proper orthogonal decomposition (POD) method, and the unsteady characteristics of aero-optical effects of the turret wake are analyzed. Although the simulated streamlines generally agree with oil flow test, some differences can be observed with respect to the flowfield structure of the turret wake. The flow around a turret can be easily separated. Further, the instability of the separated shear layer can be attributed to the K-H instability wave, resulting in the emergence of the shedding vortex streets. The unsteady complex flow in the turret wake area can be attributed to the interaction between the vortex streets and neck vortexes. The aero-optical effects of the turret wake are dominated by the steady-state aberration that accounts for 70% and can weaken the unsteady characteristics of the aero-optical effects. The wavefront is dominated by low-order modals, and the number of small-scale structures included in the modals will increase with the increasing order. According to the scaling law, the time mean value of the root-mean-square optical path difference is approximately 0.48λ under an altitude of 10 km and a turret diameter of 2 m; thus, the aero-optical effect will be further intensified, which can negatively affect the ABL performance.