Abstract: The unique characteristics of terahertz radiation make it a multifunctional tool that can be applied in various fields such as imaging, spectroscopy, communication, materials science, and biomedical applications. In this paper, the dispersion relationship of one-dimensional spin waves, magnetic domain walls, and statistical distribution of magnetic moments under thermal effects in the field of micromagnetics are studied through micromagnetic simulations based on the Landau-Lifshitz-Gilbert equation. Based on these, the three-temperature model is combined to simulate the process of terahertz waves generated by femtosecond laser irradiation on Fe thin film. The component of the electric field intensity of the simulated terahertz wave reached its maximum value at 0.3 ps. From the spectrum of the radiated electric field, it can be seen that the spectral continuity in the y-direction of the radiated electric field intensity is good, without any abrupt changes or interruptions.