The invention relates to low-yield-ratio high-strength hot-rolled Q&P steel and a manufacturing method thereof. The steel comprises the chemical components of 0.20-0.40% of C, 1.0-2.0% of Si, 1.5-3.0% of Mn, no more than 0.015% of P, no more than 0.005% of S, 0.02-0.08% of Al, no more than 0.006% of N, 0.005-0.015% of Ti, and balance of Fe and unavoidable impurities. According to the invention, through low-cost component design, on a basis of common C-Mn steel, Si content is increased such that cementite precipitation is inhibited, and austenite grains are micronized through micro-Ti treatment. Also, with a combination of hot continuous rolling process and sectioned cooling process, a structure comprising proeutectoid ferrite, martensite, and residual austenite is obtained. The yield strength is lower than 700MPa, a tensile strength is higher than 1000MPa, a yield ratio is 0.50-0.60, and alloy cost is greatly reduced.