As macroscopically weak planes Bedding defects exist extensively within shale reservoirs, have significant impacts on the communication of hydraulic fractures due to their generally long lateral extension and well-developed internal gas–liquid properties. However, the influence of bedding fractures is often neglected in traditional proppant migration models. To investigate the patterns of proppant migration and placement in bedding fractures, a fracture model incorporating bedding fractures was established using the CFD-DEM method. Numerical simulations were conducted to analyze proppant migration under different conditions of bedding fracture positions, sand concentration ratios, injection rates, and fluid viscosities. By comparing the quantity and morphology of proppants in the bedding fractures, sand injection parameters were optimized to enhance placement effectiveness. The simulation results indicate that the sandbank morphology within horizontal bedding fractures exhibits a fan-shaped distribution. As the position of the bedding fracture descends from the top to the bottom of the main fracture, the amount of proppant entering the bedding fracture gradually increases. Specifically, compared to bedding fractures located at the bottom 3/4 of the main fracture height, the quantity of proppants in bedding fractures positioned at the top 1/4 of the height increased by 206%. Additionally, an increase in the sand concentration ratio leads to a corresponding increase in the number of proppants entering the bedding fractures. For instance, a 15% sand concentration ratio results in a 35% increase in the number of proppants at the top compared to a 10% ratio. When the bedding fracture is situated in the middle to rear section of the main fracture, proppant entry is only possible when the sandbank height in the main fracture reaches the level of the bedding fracture. Furthermore, an increase in the injection rate and fluid viscosity leads to an extended proppant migration distance and, consequently, an increase in the number of proppants entering the bedding fractures. By studying the impact of different factors on proppant placement within bedding fractures, the patterns of proppant placement within bedding fractures have been clarified, and the sand injection parameters have been optimized to achieve efficient proppant placement in shale reservoirs.