The invention discloses a normalizing DH36 steel plate for wind power and a preparation method thereof. Weigh each component as required to get molten iron, molten iron KR mechanical stirring desulfurization, converter oxygen blowing smelting, LF refining, RH vacuum treatment, wire feeding, soft stirring, slab continuous casting, slab reheating, rough rolling, intermediate slab Waiting for warm cooling, finishing rolling, accelerated cooling, off-line stack cooling, ultrasonic flaw detection, shot blasting, normalizing, accelerated cooling of steel plates, fire cutting, storage. In the slab reheating stage, the heating temperature is controlled at 1150-1250°C, and the time in the furnace is not less than 1.0min / mm; the rough rolling temperature is controlled at 1000-1100°C, and the final rolling temperature is 860-900°C; the normalizing temperature of the steel plate is 880 ~900°C, the normalizing time in the furnace is not less than 2.0min / mm, and the cooling temperature after normalizing is 540‑600°C. The steel plate of the invention has good performance, low production cost, thick applicable thickness and good application prospect.