The feeding pipe in the superfine classifier is a key factor affecting the particle dispersion performance. EulerLagrange model was used to simulate the gassolid twophase flow field in the feeding pipe. An evaluation method of particle dispersion was established by introducing the nonuniformity of particle concentration distribution. The effects of the number, size and spacing assignment of the guide vanes, the gas inlet velocity, the inlet solid concentration, and particle diameter on the particle dispersion were comparatively analyzed. The numerical results show that the guide vanes can improve the particle dispersion. The particle dispersion increases with the increase of the inlet velocity, and it changes smaller with the inlet velocity above 136 m/s. With the increase of the particle size and the inlet solid concentration, the nonuniformity of particle concentration distribution increases, and the particle dispersion becomes worse. When the particle size is bigger than 50 μm, the particle dispersion is basically unchanged.