Abstract: The oscillographic impact load-displacement curve and its main physical characteristics were introduced. Taking 13MnNiMoR steel plate as an example, the influence of temperature on the load-displacement curve was analyzed, especially the change rule of crack formation energy and crack propagation energy. The results show that the ductile-brittle transition begins with the decrease of crack propagation energy. When the crack propagation energy is exhausted, the crack formation energy begins to decrease and the total impact absorption energy decreases, which corresponds to the decrease of fracture toughness section and the increase of crystalline section. The oscillographic impact curve can provide a basis for optimizing the strength and toughness of materials, and can be used to evaluate the toughness level of different materials.