Q&P steel with gradient structure and manufacturing method thereof

The invention discloses Q&P steel with a gradient structure. The Q&P steel comprises, by weight percent, 0.14-0.29% of C, 1.1-2.8% of Si, 1.8-3.0% of Mn, 0.5-1.9% of Cr, 1.5-3.1% of Al, smaller than or equal to 0.01% of S, smaller than 0.01% of P and the balance Fe. A manufacturing method of the Q&P steel includes the steps of austenitizing, carburizing, quenching, tempered carbon distributing and quenching. According to the Q&P steel and the manufacturing of the Q&P steel, technology stability and organization gradient can be ensured in production of large-size products, strength of the steel is improved, good toughness of the steel is also ensured, and low alloying cost is low.