In order to study the tracking effect of polystyrene particles in a jet,the method of large eddy simulation (LES) was adopted to simulate the jet flow field and the results were compared with the experimental data to verify the numerical model.A kind of virtual particles with different sizes and the same density as water was defined.Through the calculation based on the discrete phase model (DPM),the theoretical analysis on the responding time was adopted to compare with the results of numerical simulation to confirm the accuracy of DPM.The simulations were then performed for the flow tracking capability of the polystyrene particles with the size in the range from 1μ m to 400μ m in the jet flow field with a certain Reynolds number.And the polystyrene particles trajectories were compared with the trajectory of a massless particle.The results show that the complex flow field has a great influence on the flow tracking capability of particles.That is to say that even the particle size is very small,a certain speed deviation between the particles and fluid still exists.Besides,the speed deviation between the fluid and polystyrene particles with the size below 200 μm is smaller than 20%.