Abstract: To address the issues of improving reliability and service life of long-length mineral-insulated heating cables, a trial production of stainless steel-sheathed mineral-insulated heating cables was carried out by drawing on the continuous manufacturing process of mineral-insulated fireproof cables. Based on the mechanical property differences between metal sheath and conductor materials of mineral-insulated fireproof cables and heating cables, partial modifications were made to the existing FHL-35 mineral-insulated cable copper strip longitudinal welding production line. Samples were tested for geometric dimensions, weld microstructure, tensile properties of the stainless steel sheath and chromium-nickel alloy heating conductor, as well as magnesium oxide compaction density. Results showed that insulation and sheath thickness met the requirements, but outer diameter of the sheath was slightly off, exceeding ±0.05 mm limit specified by the standard. Some metallographic samples had incomplete weld penetration, and after rolling, cracks or root folding appeared inside the welds. The changes in material strength and elongation during vertical rolling matched work hardening rules, while the elongation changes during horizontal rolling were not clearly regular due to the annealing process. Magnesium oxide density fluctuated during the rolling process, with the compaction density ranging from 2.818 to 3.014 g·cm⁻³, clearly affected by the coupling of rolling and heat treatment processes.