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To study the uniaxial compressive behavior and constitutive relationship of high‐strength spiral stirrups confined circular ultra‐high performance concrete (UHPC) columns, an experimental investigation was presented. In this research, 14 confined UHPC columns and seven unconfined UHPC columns were tested to investigate the effects of the stirrup spacing, stirrup yield strength, and steel fibers volume content on the compressive behavior of the UHPC columns. The test results indicated that transverse reinforcement can effectively improve the deformation capacity of the UHPC columns, and all the confined UHPC columns showed ductile failure. The results also demonstrated that the high‐strength stirrup was more effective than normal‐strength stirrup for improving the post‐peak behavior of the confined UHPC. Compared with the stirrup strength, the volumetric ratio of transverse reinforcement had a more significant effect on the post‐peak ductility and toughness of the confined UHPC columns. Transverse reinforcement and steel fibers had a combined effect on improving the post‐peak behavior. Reducing the stirrup spacing or increasing the steel fibers volume content can better improve the axial compressive behavior of columns. A new constitutive model for confined UHPC was proposed. Compared with four existing models, this new model was in good agreement with the experimental curves.