Seamless steel tube armored fiber optic unit (GTXTG) is a seamless steel pipe formed by laser longitudinal welding after the steel pipe belt is formed, and the middle is filled with a special fiber paste buffer layer, which forms a good protection for the optical fiber, and can block water longitudinally, with high tensile resistance, high pressure resistance, corrosion resistance, high temperature resistance, suitable for use in extremely harsh environments, such as chemical plants, mines, underwater, ships, high temperature, low temperature, oil wells and other harsh environments.