A three-dimensional viscoelastic numerical model with Bird-Carreau constitutive equation was established by the finite element method. The movement tracking of tracer particle in laminating runner was simulated, and the effects of process parameters and structure parameters on the motion process of particle in laminating runner were analyzed. And the process parameters and structure parameters of laminated runner were optimized with analysis results. The simulation results indicate that the deviation value between actual trajectory and ideal trajectory increases with the inlet volume flow rate (Q) and horizontal flow length of runner (L) increasing, and decrease with length-width ration (K) of inlet surface increasing. Furthermore, compared with that of the model before optimization, the deviation value of optimized model is lower.