The invention relates to a
rare earth weather-resistant bridge steel plate with the yield strength being 370 MPa grade and a preparation method thereof. The preparation method comprises the steps thatsmelting and
casting are conducted; heating and rolling are conducted, specifically, the
heating temperature is 1200-1220 DEG C, the total in-furnace time is larger than or equal to 240 min, during rolling, rolling of the first stage is conducted in an
austenite recrystallization zone, the rolling starting temperature is 1130-1180 DEG C, the reduction quantity from the
first pass to the second pass is larger than 10%, and the
reduction rate of at least 1-2 of the rest passes is controlled to be 25% or above, rolling of the second stage is conducted in an
austenite non-recrystallization zone,the rolling starting temperature is smaller than or equal to 930 DEG C, the thickness of an intermediate blank is 2.0-3.5 times of the thickness of a finished product, and the finished rolling temperature is 830-850 DEG C; and cooling is conducted. The yield strength of the steel plate is larger than 370 MPa, the steel plate has the advantages of being low in
yield ratio, good
corrosion resistantperformance, low-temperature
toughness, cold-forming performance and
welding performance and capable of being used without
coating, the production technological process is simple, the production period is short, and the cost is low.