Abstract: Conventional cross-linked ethylene-tetrafluoroethylene copolymer insulated wires and cables, namely C55 wires, whose disadvantage of high fluoride off-gassing has limited their applications in aerospace manned cabin or other closed spaces. To achieve the aim of low fluoride off-gassing, the measure to decrease the amount of fluoride off-gassing was studied and a new type of C55 wires with low fluoride off-gassing was developed. Furthermore, the normal performances, extreme performances, the amount of fluoride off-gassing and service life were verified. The results confirmed the performances of C55/LF wires with low fluoride off-gassing were consistent with conventional C55 wires, in which the former could satisfy the requirements of cables for spacecraft and space station, confirmed by the actual in-orbit operation in China space station.