Abstract: Distributed tilt-wing aircraft combine vertical takeoff and landing capability with high cruise efficiency, making them promising candidates for urban air mobility applications. However, significant unsteady flow interactions among multiple propellers and between the propellers, wings, and fuselage result in pronounced coherent noise superposition effects, and aerodynamic noise has become a major factor restricting their engineering application. In this work, a 12-propeller tandem-wing distributed tilt-wing aircraft is taken as the research object. The Improved Delayed Detached Eddy Simulation (IDDES) method is employed to resolve the unsteady flow field, and the Ffowcs Williams-Hawkings (FW-H) equation is adopted for far-field noise prediction. Phase control schemes are designed separately for the typical cruise and hover conditions, and a systematic investigation is conducted into the noise reduction characteristics and underlying flow-acoustic mechanisms for phase differences ranging from 0° to 75°. The results demonstrate that phase control reconstructs the coherent superposition patterns among multiple propellers, leading to fragmentation, attenuation, or spatial redistribution of high-amplitude pressure fluctuation regions in the near field, thereby modifying the far-field noise directivity. Under cruise conditions, a phase difference of 45° achieves the optimal directional noise reduction directly beneath the airframe, with an average reduction of 11 dB along the 500 m centerline below the fuselage, 8.31 dB over the XZ plane, and a local maximum noise reduction of 18.40 dB. Under hover conditions, the same 45° phase difference yields an average noise reduction of 1.48 dB over the lower hemisphere, while a 30° phase difference is more effective in suppressing the peak sound pressure level, achieving a peak reduction of 3.1 dB over the lower hemisphere. For engineering applications, a phase difference of 45° is recommended for cruise conditions, and a range of 30°–45° is suggested for hover conditions. The findings provide a direct theoretical basis and engineering guidance for the design of low-noise active control systems and airworthiness noise verification of distributed electric propulsion aircraft.