The Wheeler model with faceted dendrite growth has been used to simulate the interface morphology evolution process of solidification for multicrystalline silicon by the finite difference method. The effects of initial nucleus, disturbance intensity and time step on the evolution process of interface morphology have been studied. The results showed that during the solidification process of multicrystalline silicon, under the initial conditions of nine nuclei, the solid-liquid interface are relatively flat, the difference of nucleus growth space is small, and it is easy to form facet cellular crystal structure which is perpendicular to the growth interface.With an increase in disturbance intensity, the side-branching occurs in facet cellular crystal, the root necking is serious and even occurs fusing. The interface disturbance with 0.01, that can truly reproduce the evolution process of polycrystalline silicon solidification interface morphology. Under the condition of guaranteeing the stability of calculation results, the time step can be increased to improve the efficiency of phase field simulation.