Abstract: Due to the presence of turbulence-driven secondary flows, the motion of inertial particles and their interaction with turbulence in particle-laden turbulent square duct flows are rendered more complex than conventional plane channel turbulence. However, there are few studies on the interphase coupling effects of heavy particle two-phase turbulent flow in square ducts, and the interaction mechanisms between micro-scale heavy particles and turbulence is still unclear. Therefore, this study employs the direct numerical simulation with a two-way coupled Lagrangian particle tracking technique to investigate the near-wall accumulation behavior of heavy particles and their influence on the instantaneous turbulent coherent structures and the mean flow field near the wall. The research focuses on dilute-phase turbulent flows in square ducts at a shear Reynolds number of Re_τ = 300, with the shear Stokes number of heavy particles ranging from St ⁺ = 25 to 260. The research results reveal that low-inertia heavy particles tend to accumulate in the central region of the duct bottom wall. In contrast, high-inertia heavy particles are more likely to aggregate in the corners on both sides of the duct bottom wall. All heavy particles tend to form elongated particle aggregation bands in the low-fluid-streamwise velocity regions. The near-wall accumulation of low-inertia heavy particles is more likely to induce a greater number of turbulent coherent vortex structures within the viscous sublayer, intensify the ejection events of turbulence but weaken the sweeping events. while high-inertia heavy particles are more likely to enhance the sweeping events in the buffer layer. Medium-inertia heavy particles, conversely, tend to suppress the generation of turbulent coherent vortex structures. Additionally, the presence of heavy particles leads to a significant reduction in the vertical secondary flow velocity of the fluid in the near-wall region.