Starting from the comparison between different methods for laying off circular curve,this paper presents a completely new method of deflection angles at deflection point,which is easy to compute,convenient to set out,increasing exactness and reducing amount of work.

Making use of the construction guideline to lay off the major points for the transition curve of the road with the distancer and polar method, and making the measuring and setting in detail of the points on the transition curve of the road with declination method, can increase effectively the accuracy of the points location of all major points, reduce erro.

By combining with example of the construction line-putting of Xiqu Fen river Bridge in Gujiao city,the paper introduces two kinds of curve coordinate calculation method,that is tangent offset method and the center declination method,according to comparison analysis and chooses a new method,center declination method which is easier to operate than the tangent offset method and makes less mistakes.