Abstract:The effective length is an important parameter for calculating the bearing capacity of compression members.However, for the simplified design method adopted in the code, the components are analyzed separately, which is divorced from the constraints of the original overall structural environment and can not meet the actual needs of pier calculation.The main bridge of Wachang bridge adopts the whole double main piers. The left and right spans are connected by setting transverse braces, and the overall stiffness is large. The critical load of the member is obtained by establishing the spatial finite element compression bar model, and the calculated length coefficient of the pier is deduced from the Euler formula, so as to obtain a value closer to the actual situation of the project, which has certain guiding significance for similar bridges.