The deposition of particulate matter in heat exchanger channels can greatly reduce their heat transfer efficiency, and a better understanding of the deposition characteristics of particulate matter in heat exchanger channels is essential for improving heat exchanger performance. The deposition characteristics of particles in a three-dimensional dimpled dimple channel were simulated using the Reynolds Stress Model (RSM) and Discrete Particle Model (DPM). The flow structure, secondary flow, temperature distribution and particle deposition distribution in the dimpled dimple channel were analyzed and investigated after mesh-independence testing and numerical validation. The results showed that the main mechanisms affecting the particle deposition characteristics in dimpled dimple channels were gravity, thermophoretic forces, turbulent flow structure, secondary flow and particle inertia, and the effects of these mechanisms change significantly with particle size. For small particles (dp≤10 μm), the presence of the dimpled dimple structure promoted deposition; however, for large particles (dp>10 μm), its presence had only a small effect on the distribution of particle deposition locations.