The invention discloses methods for preparation of low-carbon high-strength ship plate steel and regulation and evaluation of a yield ratio, and belongs to the field of metal materials. According to the methods, the required yield ratio is achieved through process regulation. Materials comprises the following components of 0.05wt%-0.07wt% of C, less than or equal to 0.001wt% of Si, 1.2wt%-1.5wt% of Mn, 5.1wt%-5.3wt% of Ni, 0.45wt%-0.80wt% of Cr, 0.55wt%-0.80wt% of Mo, 0.03wt%-0.04wt% of V, 0.05wt%-0.06wt% of Nb, 0.008wt%-0.0012wt% of Ti, 0.02wt%-0.03wt% of Al, less than or equal to 0.01wt% ofP, less than or equal to 0.004wt% of S, and the balance Fe and certain unavoidable impurities. The preparation method has the advantages that under the low-carbon and low-alloy condition, the high material strength is guaranteed through the reinforcing effect of nano-particles; when the chemical components of the materials are certain, the shape, the type, the proportion and the like of phases canbe changed through rolling and heat treatment processes so as to obtain the required yield ratio; and the methods relate to the high-strength and ultrahigh-strength ship plate steel, and have a wideapplication prospect.