For the cross-river bridges, in addition to the overloading, the excessive flood is another major risk factor for bridge safety. A large number of examples of bridge water damage data show that the failure forms of crossing river bridges are prone to occur under the operation of exceeding the standard flood, such as foundation erosion and hollowing leading to insufficient bearing capacity of pile foundation, bridge dislocation caused by sliding of plate rubber bearing, direct floating sliding of superstructure, and direct transverse overturn the superstructure. Therefore, taking four important cross-river bridges on Nanfei River in Hefei City as an example, the failure forms of bridge under the exceeding flood are analyzed in order to provide the reference for the analysis on the failure forms of the similar bridge under the flood condition.