Cold-rolled weathering resistant steel and preparation method thereof

The invention discloses cold-rolled weathering resistant steel and a preparation method thereof. The cold-rolled weathering resistant steel comprises the following chemical components of, by weight, 0.05%-0.08% of C, 0.25%-0.40% of Si, 0.25%-0.40% of Mn, 0.060%-0.100% of P, less than or equal to 0.020% of S, 0.008%-0.030% of Als, 0.12%-0.20% of Ni, 0.25%-0.40% of Cu, 0.30%-0.50% of Cr, less than or equal to 0.0080% of N, and the balance Fe and inevitable impurities. Reasonable chemical component design is achieved, noble metal alloys such as Ti, Nb and B are not added, a hot rolling process, acold rolling process, a continuous annealing process and a flattening process are controlled, so that the cold-rolled weathering resistant steel with good surface quality is obtained, in the case ofthe cold-rolled weathering resistant steel, the yield strength is larger than or equal to 350 MPa, the tensile strength is larger than or equal to 500 MPa, the A50 elongation percentage is larger thanor equal to 30%, and the good atmospheric corrosion resistance and welding performance are achieved.