The invention relates to a quenched and tempered steel plate with the yield strength being 420 MPa grade for a building structure and a production method of the quenched and tempered steel plate. The component design that Nb and Ti microalloying treatment is conducted on the basis of a Fe-Mn-C system is adopted, and the steel plate material is prepared from the chemical components including 0.13%-0.18% of C, 0.20%-0.50% of Si, 1.40%-1.70% of Mn, less than or equal to 0.015% of P, less than or equal to 0.005% of S, less than or equal to 0.30% of Cr, less than or equal to 0.30% of Mo, less than or equal to 0.30% of Ni, less than or equal to 0.30% of Cu, 0.020%-0.050% of Al, less than or equal to 0.015% of V, 0.025%-0.050% of Nb, 0.010%-0.020% of Ti, less than or equal to 0.006% of N and the balance Fe and inevitable impurity elements. The production process comprises the following steps that raw materials are smelted in a converter, refined outside the converter and refined in an RH furnace in sequence to obtain molten steel with higher purity, the molten steel is poured to form a steel billet being 370 mm-450 mm, then reasonable steel billet heating, rolling, on-line direct quenching and tempering heat treatment technologies are adopted, and the steel plate material with the yield strength being 420 MPa grade is suitable for large-scale steel structure constructional engineering such as high-rise buildings, large-span stadiums, airports, exhibition centers and industrial factory buildings is obtained.