Cable Mould Melt Joint (MMJ) is an abbreviation for Mould Melt Joint. It is a cable joint manufactured through an extrusion moulding and cross-linking process, using raw materials, main structure, and specifications consistent with the connected cables. This process fuses the high-voltage shielding, insulation, and outer shielding of the cable to form a continuous electric field shielding body with homogeneous material properties, eliminating stress cones and interfacial air gaps.

The MMJ is not an accessory isolated from the cable; rather, based on cable principles and structure, it creates a new, continuously and equivalently regenerated cable section.