The effective length coefficient of a pier is a controlling factor affecting the safety and economic index of bridge structures.The values of the effective length coefficient of compression members in Chinese and foreign codes are basically similar，and they are only applicable to ideal boundary conditions.In practical application，it is necessary to make appropriate adjustments according to the specific structural form.In order to get the value closer to the actual situation of the structure，this paper analyzed the overall stability of the structure and investigated the influence laws of different factors on the effective length coefficient of the continuous rigid frame bridge in the completion stage and the maximum double cantilever stage，mainly including different pier types，pier height，pile foundation flexibility，adjacent span boundary，single pier instability，or overall instability.The results show that the effective length coefficient of different pier types along and across the bridge is not a fixed value，and the variation of the effective length coefficient with the pier height is not a simple linear relationship.Due to the influence of pile foundation flexibility，the result will increase by about 20%，and the influence across the bridge direction is more significant than that along the bridge.After considering the influence of connecting piers，the value of the effective length coefficient is larger.It is necessary to consider the overall buckling response of each pier under axial load at the same time.The distribution range of the effective length coefficient along the bridge under the maximum double cantilever condition in the construction stage of a continuous rigid frame is 1.20?1.35.