Strategic petroleum reserve tank steel plate based on oxide metallurgy and manufacturing method thereof

The invention discloses a strategic petroleum reserve tank steel plate based on oxide metallurgy and a manufacturing method of the strategic petroleum reserve tank steel plate. The yield strength of the steel plate is large than or equal to 490 MPa, the tensile strength is 610-730 MPa, and the yield ratio is smaller than or equal to 0.90. The manufacturing method comprises the steps that a continuous casting billet is manufactured, heated for heat preservation, roughly rolled, finely rolled, directly quenched and cooled at the speed being larger than or equal to 50 DEG C/s, heated, tempered and subjected to air cooling. The steel plate is also applicable to manufacturing of large strategic petroleum reserve tanks with the volume being 100000 m , 150000 m or more; when the steel plateis subjected to large heat input welding when heat input is large than 200 KJ/cm, after welding, the welding heat affected zone -20 DEG C impact energy is not lower than 80 J; a two-face two-pass X-type welding way which sets limi