The accumulation of particles in the internal cooling channel reduces the cooling effectiveness of the turbine blades and even affects the safe operation of the aero engine. Discrete phase-CFD simulations of particles deposition were performed in the U-bend ribbed passage by applying Euler–Lagrange method. Reynolds Average Navier–Stokes method was used for the gas phase calculation. The realizable k–ε turbulence model and enhanced wall treatment were adopted. The discrete phase was solved by using Lagrangian with random walk model. A particle deposition model was implemented by using user-defined functions. The Reynolds numbers of 30,000, 23,000, and 15,500 were studied. Particles diameters in the range 1–20 μm were considered. The particles deposition distribution of different locations is obtained in this study, and the influence of the Reynolds numbers and particle diameters on particles deposition performance are analyzed. Results show that the first row of ribs has a protective effect on the back row of ribs. The increased Reynolds number and increased particles diameter promote the deposition of particles on the wall.