Abstract: In response to the domestic demand for developing 960 MPa grade explosion-proof steel and evaluating its blast resistance and mechanism, the mechanical properties, microstructure, and blast resistance of a newly developed high-strength-toughness 960 MPa grade explosion-proof steel (BR900) were investigated. The yield strength of BR900 steel is 1 002 MPa, and its impact energy at -40 ℃ exceeds 200 J. The excellent combination of strength and toughness is mainly attributed to the fine-grain and multiphase microstructure. Dynamic mechanical behavior at high strain rates was analyzed through high-strain-rate tensile tests and constitutive model fitting. The blast deformation behavior of 4 mm thick test plates under a 60 g TNT air blast load was studied using small-scale explosion tests. The results indicate that BR900 steel exhibits excellent blast resistance due to its favorable strength-toughness match and strain hardening capability.