Prestressed reinforced concrete simple supported slab bridge is still used as one of the preferred bridge type designs because of its simple structure, easy construction, strong adaptability and relatively economic advantages. But there are also some shortcomings. Many bridges have different diseases shortly after opening to traffic. The transverse and longitudinal cracks of beam and slab are more common, which will have a greater impact on the safety and durability of bridge structures. Based on a pre-tensioned prestressed concrete hollow slab bridge, this paper analyses the causes of the abnormal transverse joints at the end of the bridge. Through the finite element analysis software ABAQUS, a 1/4 model of a single beam is established to analyze the effect of the transverse cracks at the end of the beam under overload and progressive loss of prestress. The results show that with the increase of load and the continuous loss of prestressing force, the damage of concrete near the end of beam is more serious, and the stress and strain reach the maximum first, and crack occurs before other parts. On this basis, TRM reinforcement method is used to reinforce damaged beams. The overall bearing capacity and failure mode of damaged beams are improved significantly.