In this paper, the transfer matrix method is used to study the characteristics of the photon localization in the mirror heterogeneous structure which has three periods and one-dimensional photonic crystal in uniaxial stress change. In a mirror structure triply-periodic photonic crystal system, its mirror structure destroys the orderliness of the photonic crystal and produces a defect state, so the transmission peaks of a photon localization appear in the photonic band gap wider center. The study shows that when a uniaxial stress is exerted on the mirror structure with three-periodic photonic crystal, the photon localization transmittance peak dramatically changes with the stress. When a weak external mechanical stress is applied to the photonic crystal, photonic crystal forms a tensile strain which induces the change in the photonic crystal structure and significantly affects the rate of the transmittance peak transmittance of photon localization. The results show that the transmission peak transmittance is significantly influenced by the uniaxial stress. These features provide a theoretical reference for the design of ultra-high-sensitivity pressure sensor with the photonic crystal structure.