Abstract: Three buckling-restrained braces (BRBs) assembled with section steel were designed using novel soft steel LY315 as the core material. Cyclic loading tests on three specimens were conducted to analyze the mechanical properties and the energy dissipation of the new type of BRBs. The results indicate that the structure of BRBs is reasonable and all specimens exhibit a full hysteretic curve and stable energy dissipation performance. The ultimate ductility coefficients of specimens were greater than 15. The strain hardening coefficients were between 1.21 and 1.29. The equivalent damping ratios were between 0.442 and 0.465. The cumulative plastic deformations were more than 500 times the yield displacement. The fatigue loading was analyzed. All performance parameters were able to meet the requirements in JGJ 297-2013 'Technical specification for seismic energy dissipation of buildings', indicating excellent low-cycle fatigue behavior of the BRBs.