Abstract: There is a problem about joint connection in the construction process of prefabricated UHPC bridge deck, the fiber discontinuity of the joint interface makes the problem more considerable. In order to effectively improve the mechanical properties of UHPC joints, this study realizes the fiber continuity of UHPC joint interface by using sponge adsorption retarder to block pouring and high-pressure water gun to wash the joint section. Based on the study of the mechanical properties of joint plate, the design method for fiber continuous joint is studied by combining test and finite element analysis, and the calculation method for the flexural capacity of UHPC fiber continuous joint is deduced. And the results obtained: Numerical models with cohesive model were built and verified with test results to explore the force transferring mechanism, and the maximum error between the bearing capacity and the ultimate load of the structure calculated by the finite element model and the measured results is only 3.9 % and 2.1 %, respectively; Changing the length of the joint fiber cannot effectively improve the bearing capacity of the specimen; The fiber continuous joint specimen shows a similar deformation law to the cast-in-place specimen, and the cracking load reaches 88.2 % and 83.1 % of cast-in-place specimen, respectively.