Deformation occurred in the bridge usage process due to the effort of self and external load. These deformations generally occurred in the absolute and relative position change of self and co-component including displacement, settlement, bending, distortion etc. The scope of this paper is to design a bridge geometry detection program system which using based on online PDA (Personal Digital Assistant). In the high speed data acquisition model, it can acquire the data of deflection, horizontal and vertical alignment, horizontal displacement in a real-time and digital way. In the data analysis module, it can evaluate the bridge safety and generate testing report through the comparison of the corresponding curves between the displacement and working positions.