Marine steel and production method thereof

The invention provides marine steel and a production method thereof. The marine steel comprises the following chemical components in percentage by mass: more than or equal to 0.06 wt% and less than or equal to 0.08 wt% of C, more than or equal to 0.10 wt% and less than or equal to 0.20 wt% of Si, more than or equal to 0.9 wt% and less than or equal to 1.1 wt% of Mn, less than or equal to 0.015 wt% of P, less than or equal to 0.005 wt% of S, more than or equal to 0.018 wt% and less than or equal to 0.045 wt% of Als, more than or equal to 0.02 wt% and less than or equal to 0.03 wt% of Nb, less than or equal to 0.02 wt% of Ti, more than or equal to 0.0075 wt% and less than or equal to 0.011 wt% of N, more than or equal to 0.03 wt% and less than or equal to The center segregation and center porosity of a plate blank of the marine steel are smaller than or equal to C1.0 level, and the average size of inclusions of the marine steel is 1t; the Z-direction performance is excellent, the stretching layering or suspecte