Abstract: The effect of width of anti-slide piles on soil arching between piles directly related to the rationality of design of the section and the space of piles.By the centrifuge model tests,the phenomenon was observed that the larger the width of piles was,the more stable of the soil arching was.Based on the centrifuge model,the numerical simulation method was adopted to analyze the relationship between the bearing capacity of soil arching and the width of piles.It was indicated that if the space between piles was constant the bearing capacity of soil arching gradually increased with the increase of width of piles,but the increasing velocity gradually became slow.It was illuminated that the effect of the width of piles on the bearing capacity of soil arching vanished with the increasing of pile width.If the ratio between the space and the width of piles was constant,the bearing capacity of soil arching descended when the width and the space of piles increased,and the descending gradient gradually increased.It was indicated that the space between piles acted as the dominator to bearing capacity of soil arching,so the contribution of increasing the width of piles for the bearing capacity of soil arching was far less than the weakening effect due to increasing the space between piles.It was indicated that the relationship between the bearing capacity of soil arching and the width of piles was non-linear,and it should be considered when the numerical model of reasonable pile space was established.