The invention discloses 225MPa level weather resistance low-yield-point damper steel and a preparing method. The 225MPa level weather resistance low-yield-point damper steel comprises chemical components including 0.03 wt%-0.06 wt% of C, 0.01 wt%-0.03 wt% of Si, 0.15 wt%-0.25 wt% of Mn, smaller than or equal to 0.020 wt% of S, 0.040 wt%-0.065 wt% of P, 0.040 wt%-0.070 wt% of Als, 0.35 wt%-0.60 wt%of Cr, 0.25 wt%-0.45 wt% of Ni, 0.20 wt%-0.40 wt% of Cu, smaller than or equal to 0.0040 wt% of N, smaller than or equal to 0.0020 wt% of O, smaller than or equal to 0.0001 wt% of H and the balance Fe and inevitable impurities. A 225MPa level weather resistance low-yield-point damper steel plate and a steel strip are obtained through the steps of blast furnace molten iron pretreatment desulfuration, molten iron converter smelting, molten steel deoxygenation alloying, molten steel LF furnace refining, molten steel VD vacuum refining, molten steel pouring, steel blank heating, steel blank descaling, steel blank controlled rolling and controlled cooling, refined rolling, cooling and the like. The defect that existing low-yield-point damper steel is poor in weather resistance is overcome, accordingly, the service life of a damper is prolonged, and the using and maintaining cost is reduced.