Simulation models for accident section on freeway are built in microscopic traffic flow simulation environment. In these models involving 2-lane,3-lane and 4-lane freeway,one detector is set every 10 m to measure section running speed. According to the simulation results,speed spatial distribution curves for traffic accident section on freeway are drawn which help to determine dangerous sections on upstream of accident section. Furthermore,the speed spatial distribution models are obtained for every speed distribution curve. The results provide theoretical basis for determination on temporal and spatial influence ranges of traffic accident and offer reference to formulation of speed limit scheme and other management measures. Simulation models for accident section on freeway are built in microscopic traffic flow simulation environment. In to the models involving 2-lane, 3-lane and 4-lane freeways, one detector is set every 10 m to measure section running speed. results, speed spatial distribution curves for traffic accident section on freeway are drawn which help to determine dangerous sections on freeway are drawn which help and spatial influence ranges of traffic accident and offer reference to formulation of speed limit scheme and other management measures.