High-temperature 260 DEG C resistant tightly-packaged fiber and preparation process thereof

The invention discloses a high-temperature 260 DEG C resistant tightly-packaged fiber and a preparation process thereof. The high-temperature 260 DEG C resistant tightly-packaged fiber is characterized in that a coating layer is arranged on the periphery of a fiber core, and a tightly-wrapping layer is arranged on the periphery of the coating layer. According to the preparation process, a fiber core comprises a single-mode fiber core and a multi-mode fiber core, wherein the single-mode structure has a thickness of 9/125mu m and the multi-mode structure has a thickness of 50/125mu m or 62.5/125mu m; polyimide is coated on the coating layer by using a coating device, a tightly-wrapping fiber is normally laid and installed at a temperature of -65 DEG C by the coating layer, wherein the polyimide resists the temperature grade of -65 DEG C- +260 DEG C, the outer diameter of the coating layer is 155mu m; and soluble polytetrafluoroethylene (FPA) thin-wall-extruded by adopting a high-temperature extruding machine in the tightly-wrapping layer, and the tightly-wrapping layer resists a high temperature of 260 DEG C. The high-temperature 260 DEG C resistant tightly-packaged fiber has the characteristics of high temperature 260 DEG C and low temperature -65 DEG C resistance, high strength, bending resistance, impact resistance, ageing resistance, long service life, corrosion resistance, inflaming retarding and the like, and is suitable for high-speed signal transmission under aerospace, electrons and onboard special environment conditions.