The invention relates to a thermally-formed steel plate with high fatigue strength for axle housing of heavy truck, and a manufacturing method thereof. The steel plate is composed of the following components in percentage by weight: 0.1 to 0.22% of carbon, 0.1 to 0.65% of silicon, 0.8 to 1.8% of manganese, not more than 0.55% of copper, not more than 0.025% of phosphor, not more than 0.003% of sulfur, 0.012 to 0.06% of niobium, 0.015 to 0.07% of vanadium, 0.012 to 0.05% of titanium, 0.012 to 0.045% of aluminum, 0.1 to 0.55% of chromium, and the balance being Fe and inevitable impurities. A niobium-vanadium alloy is added, the crystals are refined and toughened, impurities and harmful gas are removed in the assistance of a refine technology, and thus the steel is more pure, and obtains more excellent toughness. Furthermore, a controlled rolling technology is adopted to process the steel plate, the tissue internal stress is eliminated, and the ductility and toughness are improved, so the steel plate has a good welding performance. Moreover, the steel plate is subjected to a desulfurization process and a degassing process, the limiting performance of fatigue strength is greatly improved, and the service life is prolonged.