The preparation technology of reactive powder concrete (RPC) and slurry infiltrated fiber concrete (SIFCON)were adopted respectively, according to the multi scale structure characteristic of cementitious composites, the preparation technology of the ultra-high-toughness cementitious composite(UHTCC) reinforced by calcium carbonate whisker and micro steel fiber were studied, and the compressive strength, flexural strength, bending strength and mechanical properties uniaxial tension of different mixture proportions were tested. The ratio of flexural-compressive strength, toughness index and other more index were used to evaluate the toughness of the UHTCC. The experimental results indicate that the compressive strength, flexural strength, bending strength, ductility and toughness of UHTCC are much higher than those of general steel fiber concrete. The bending strength of UHTCC and the toughness index I₂₀ are up to 65.1MPa and 49.21 respectively. False strain-hardening behavior of UHTCC are achieved under uniaxial tension. The ultimate tensile strain of UHTCC can reach 4%~8%. Compared to RPC technology, higher toughness are obtained using SIFCON technology.