Textile reinforced ultra-high performance concrete (TR-UHPC) utilizes the synergistic reinforcing mechanism of short steel fibers and textile to further improve the mechanical properties and strain hardening effect of ultra-high performance concrete (UHPC). To investigate the flexural properties of TR-UHPC and synergistic effects of textile and steel fibers, four-point bending tests were conducted. A design method for TR-UHPC flexural members based on a tension-stiffening model and a bending model was proposed. The effect of tension-stiffening on the flexural responses of TR-UHPC was analyzed. The results show that the flexural capacity of TR-UHPC specimens increases with the increase of steel fiber dosage. The maximum flexural strength can be obtained at a steel fiber volume fraction of 1.0% or 1.5%, indicating that the content of steel fiber can be effectively reduced. The prediction data by the proposed model are in reasonable agreement with the experimental results. The proposed model can be used to predict the load capacity of TR-UHPC flexural member with given materials, or guide the material design according to the demands of structural performance.