Phase-changing materials (PCMs) are widely used thermal-energy-storage substances that utilize the absorption and emission of heat during the solid–liquid–solid phase change of a substance to store and release thermal energy, which is closely related to their structural properties. This paper combines THz technology with microfluidic technology to investigate the THz spectral properties of phase-changing thermoregulated emulsions and the results show that: with the increase of the applied magnetic field strength, more molecules are magnetized and arranged with orientation, and the transmission intensity of THz increases; with the increase of the applied electric field strength, the bond length of covalent bonds becomes larger, and the transmission intensity of THz increases; during the cooling process, the free energy of molecules decreases, and the transmission intensity of THz increases. The results provide technical and data support for the in-depth study of phase-changing thermoregulated emulsions, which is important for the fine study and improvement of properties in different environments in aerospace and coating fields.