Based on the NaSh model, considering the influence of traffic accident and maintenance of highway sections on traffic flow, the cellular automaton model of highway traffic flow under the lane control is established when accident occurs. And the relevant data of the model are calculated. Through analyzing the results of numerical simulation it is found that the accident has a great influence on the highway traffic flow and considerably on traffic flow density within a certain range. And the influence of the accident blocking point on traffic flow on lane 1 is less than on lane 2. Meanwhile, in this range of traffic flow density, the longer the blocking time and the length of blocking section, the greater the influence of traffic flow is.