This research mainly focuses on the numerical simulation of the flexural performance of the precast ultra-high performance concrete beam. Using a nonlinear three-dimensional finite element model, the concrete damage plasticity model and material properties obtained from uniaxial compression and tensile laboratory tests were used to simulate the Segway precast beams of UHPC in the commercial finite element software package ABAQUS. This study includes the influence of various parameters: concrete strength, pre-compression stress, number of teeth and depth of teeth. The finite element simulation of the flexural performance of the UHPC segmental beam is performed and the results of the field model test are compared. The results show that the prediction of the flexural performance of the prefabricated UHPC segmental beam is in good agreement with the test data. The pre-compression stress mainly affects the ductility of the test beam, but has little effect on its load carrying capacity. For spliced beams, the lower the number of key teeth, the higher the flexural capacity, and the ductility and flexural capacity decrease as the number of key teeth increases. The finite element simulation shows that the flexural capacity of the test beam increases as the concrete strength increases. The number of key teeth has little influence on the flexural capacity, and the single-teeth test beam has the largest flexural capacity. Due to the tapered effect of the key teeth, the greater the depth of the key teeth, the greater the bending capacity of the test beam.