Serious interference between motor vehicles and pedestrians happens at crosswalk when pedestrian flow is large. In this paper, cellular automata models are used to model the behavior of mutual interferences between pedestrians and vehicles at crosswalk by introducing conflict interference rules between pedestrians and vehicles. Numerical simulations are carried out to study the fluxes of vehicle and pedestrian, influenced by the parameters, such as the arrival rates, pedestrian waiting time and the pedestrian's sensitivity coefficient to vehicle. Simulation results show that the model can reflect the interference characteristics between pedestrians and vehicles well. With the increase of threshold that pedestrians cross the traffic lane riskily, motor vehicle flow increases but pedestrian flow decreases. With the increase of pedestrian's sensitivity coefficient, pedestrian avoiding probability decreases, motor vehicle flow decreases, pedestrian flow increases. The results have certain significance for the control and management of mixed traffic.