Dong ping bridge as the background in the paper, using a bridge-specific finite element software MIDAS / CIVIL Spaces to set up full-bridge model. On the calculation of a variety of conditions, deflection value and stress value under a variety of working conditions, to assess the safety of its structure . The calculation results show that: under the design load of the bridge, the maximum deflection value of less than the value of standardizing provisions, under the load combination the maximum stress does not exceed the material yield strength and have a certain stress safety margin.