In the power system

when the cable is subjected to strong impulse current

it will work in the temperature field higher than 10% of the conductor’s maximum operating temperature. The long-term high-temperature aging condition has a great negative effect on the optical fiber in the optical unit of Optical Fiber Composite Low-Voltage Cable（OPLC）

which seriously affects the safe operation of the entire power grid. Aiming at the above problems

in order to study the mechanical properties of single-mode fiber before and after heating

the damage degree of high temperature aging to optical fiber is analyzed. In this paper

the mechanical properties of single-mode fiber

such as breaking strength

elongation at break and stripping force of coatings

are tested at different temperatures and aging periods by emulating the temperature field of OPLC conductors 10% higher than that of polyvinyl chloride insulated conductors. Based on the test data

the change trend of mechanical properties of optical fiber before and after aging under this temperature field is studied by using the statistical method of linear fitting. The results show that the stress corrosion sensitivity parameters of optical fiber in OPLC are more sensitive to heat than the coating peeling force characteristics. With the increase of aging time

the difference between the coating stripping force and the stress corrosion sensitivity parameters is larger and the heat resistance is worse. Based on the test results of mechanical properties

the suggestion of adding heat-resistant layer of optical unit is proposed in this paper.