Abstract: The Gleeble-3500 thermal simulation experiment machine was used to determine the phase transition temperature of low-carbon steel and the maximum precipitation temperature of second-phase particles, and the influence of the coiling temperature on the second phase particle precipitation was studied.The results show that the second phase particle precipitation during the transformation from austenite to ferrite is more; with the decrease of coiling temperature, the solid solubility of the microalloying elements in the steel gradually decreases, and the precipitation power gradually increases, but the diffusion power decreases to a certain extent, the second phase particle precipitation increases first and decreases, and the precipitation amount of the second phase particles is the largest at 750 ℃.The second phase particles are mainly carbides and sulfides, with less nitrides; the reduction of the coiling temperature makes the element difficult to diffuse, thus inhibiting the precipitation of the second phase particles.