Abstract: The traditional route setting-out mostly uses deflection angle method and tangent off-set method etc.In these methods, setting-out is very difficult when the relief is complex and disadvantageous for the two points to be watched each other.For Large-sized curve bridges, the ordinary setting-out method is unable to meet the demand of accuracy.However, the method of directly calculating the planimetric coordinates of the centre line on the road and the calculating program of road design can completely solve the problems above.The practise proves that the new method is pratical, reliable and more accurate and is suitable for various kinds of setting-outs on road construction and designing calculation of routine.