The invention discloses high-strength steel with the yield strength of 700MPa and a TMCP manufacturing method, and belongs to the technical field of production of the high-strength steel. The high-strength steel comprises chemical compositions including, by mass, 0.07% to 0.10% of C, 0.15% to 0.40% of Si, 1.20% to 1.80% of Mn, 0% to 0.40% of Cr, 0% to 0.30% of Mo, 0% to 0.30% of Ni, 0% to 0.0020% of B, 0% to 0.070% of Nb, 0% to 0.070% of V, 0% to 0.020% of Ti, 0% to 0.050% of Alt, not larger than 0.015% of P, not larger than 0.010% of S, 0.40% to 0.50% of carbon equivalent Ceq, and the balanced Fe and inevitable impurities. The method comprises the steps of slab casting after smelting, slab heating, billet heating, rolling and water cooling. The high-strength steel has the advantages that a performance index is stable, the requirement of the ultrahigh-strength steel for the performance can be completely met, and the good strength, plasticity, toughness and welding performance can be achieved.