Abstract: The landing gear is recognized as a significant source of noise during the takeoff and landing phases of civil aircraft operations. Understanding the mechanisms behind its noise generation and exploring effective control methods are crucial for improving overall noise management in aviation. This article presentd a detailed numerical study employing the Lattice Boltzmann Method (LBM) to simulate the three-dimensional unsteady flow around the LAGOON (LAnding Gear nOise database for civil aviation authority validatiON) model of landing gear. The study applied the Ffowcs Williams-Hawkings (FW-H) equation to compute far-field noise levels. Initially, the research investigated the impact of mesh resolution on simulation results by comparing them against wind tunnel data to verify the accuracy of the numerical calculations. Subsequently, the study analyzed the noise generation mechanisms and spectral characteristics, providing a comparative assessment of the effects of different FW-H integration planes on noise predictions. This analysis highlighted the critical role of integration surface selection in ensuring prediction reliability. Furthermore, the research evaluated flow control strategies, specifically examining the noise reduction effect of cavity filling in the landing gear model. The findings indicate that using a penetrable surface as the FW-H integration surface yields closer agreement with experimental measurements compared to a solid surface. Additionally, cavity filling significantly suppresses resonance phenomena, reducing the total sound pressure level by approximately 3.0 dB in both the far-field flyover and sideline directions. This finding suggests a viable approach for aircraft noise reduction design. This study systematically validates the applicability of LBM based prediction framework for landing gear aeroacoustics. The elucidated noise generation mechanisms and the noise reduction effect of the cavity filling scheme provide methodological insights and data support for subsequent engineering-oriented low-noise landing gear design.