Abstract: The insulation core of medium and high voltage cables will always generate cross-linking byproducts in the cross-linking reaction. Some of them will be attached to the insulation shielding surface, and some of them will form coke scale on the inner wall of cross-linked pipes. By installing a filter device at the outlet of the cooler fan, the gas cross-linking byproducts in nitrogen will be filtered out, eliminating the adhesion on the insulation shielding surface,preventing coke formation on the inner wall of cross-linked pipes, keeping the insulation shielding surface clean and bright.