Based on practical field expericnces, this paper discusses the indirect determination method of the length of rails in joint areas and the computation of the length of the rail at a track bond,by the use of the principle of tangent offset.

A set of formula and method is derived and statement to survey curve with chord offset method by comparing three methods.

The application of field layout in mountain highway plane curve by the baseline offset method;

The setting of road shape instruction along highway in mountain area was discussed using tangent offset method in road survey.

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.

Measuring technique such as coordinate method ,arc chord offset method and internal control measurement are applied .

In the course of surveying,many methods were used such as direction intersection method,ultimate corrdinate method,arc chord offset method,etc.